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Chinese Chemical Letters
Chinese Chemical Letters
主管 : 中国科学技术协会
刊期 : 月刊主编 : 钱旭红
语种 : 英文主办 : 中国化学会、中国医学科学院药物研究所
ISSN : 1001-8417 CN : 11-2710/O6本刊创办于1990年7月,是由中国化学会主办,中国医学科学院药物研究所承办的核心期刊。本刊由著名化学家梁晓天院士任主编,其内容涵盖化学研究的各个领域,及时报道我国化学界各个研究领域的最新进展及世界上一些化学研究的热点问题。本刊自1993年起为SCI、CA、日本科技文献速报等收录,2000年美国化学文摘引用中国期刊频次中位列第四。展开 > - 影响因子: 9.4
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Synthesis of a new ratiometric emission Ca2+ indicator for in vivo bioimaging
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Synthesis of a water-soluble macromolecular light stabilizer containing hindered amine structures
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Fluorine-containing agrochemicals in the last decade and approaches for fluorine incorporation
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Superiority of poly(L-lactic acid) microspheres as dermal fillers
Achieving high energy densities for all-solid-state lithium batteries is restricted by the poor high voltage stability of solid electrolytes. Herein, F-doping strategy is successfully employed on Li3InCl6 to obtain enhanced voltage stability and electrode compatability towards bare LiNi0.7Mn0.2Co0.1O2 at high voltages. The optimized Li3InCl5.5F0.5 electrolyte exhibits a decreased conductivity of 1.00 mS/cm, a wider voltage window, and improved electrochemical performance in solid-state batteries when cycled at upper cut-off voltages of 4.5 and 4.8 V (vs. Li+/Li0). The generation of more stable LiInF4 phase in the cathode mixture of Li3InCl5.5F0.5-based battery ensures superior electrochemical performances compared to the Li3InCl6-based battery. The former battery exhibits a higher discharge capacity of 218.9 mAh/g and coulombic efficiency of 86.7% for the first cycle, and retains 80.0% of its original value after 100 cycles when cycled in the range of 3.0–4.5 V (vs. Li+/Li0). In contrast, the Li3InCl6-based battery exhibits lower capacities and faster degradation under the same conditions due to the formation of InCl3 phase with poor electrochemical stability. This work facilitates the advancement of high energy density solid-state battery technologies by utilizing high-voltage cathodes.
Conductive hydrogel membranes with nanofluids channels represent one of the most promising capacitive electrodes due to their rapid kinetics of ion transport. The construction of these unique structures always requires new self-assembly behaviors with different building blocks, intriguing phenomena of colloidal chemistry. In this work, by delicately balancing the electrostatic repulsions between 2D inorganic nanosheets and the electrostatic adsorption with cations, we develop a general strategy to fabricate stable free-standing 1T molybdenum disulphide (MoS2) hydrogel membranes with abundant fluidic channels. Given the interpenetrating ionic transport network, the MoS2 hydrogel membranes exhibit a high-level capacitive performance 1.34 F/cm2 at an ultrahigh mass loading of 11.2 mg/cm2. Furthermore, the interlayer spacing of MoS2 in the hydrogel membranes can be controlled with ångström-scale precision using different cations, which can promote further fundamental studies and potential applications of the transition-metal dichalcogenides hydrogel membranes.
Spin-orbit coupling (SOC) plays a vital role in determining the ground state and forming novel electronic states of matter where heavy elements are involved. Here, the prototypical perovskite iridate oxide SrIrO3 is investigated to gain more insights into the SOC effect in the modification of electronic structure and corresponding magnetic and electrical properties. The high pressure metastable orthorhombic SrIrO3 is successfully stabilized by physical and chemical pressures, in which the chemical pressure is induced by Ru doping in Ir site and Mg substitution of Sr position. Detailed structural, magnetic, electrical characterizations and density functional theory (DFT) calculations reveal that the substitution of Ru for Ir renders an enhanced metallic characteristic, while the introduction of Mg into Sr site results in an insulating state with 10.1% negative magnetoresistance at 10 K under 7 T. Theoretical calculations indicate that Ru doping can weaken the SOC effect, leading to the decrease of orbital energy difference between J1/2 and J3/2, which is favorable for electron transport. On the contrary, Mg doping can enhance the SOC effect, inducing a metal-insulator-transition (MIT). The electronic phase transition is further revealed by DFT calculations, confirming that the strong SOC and electron-electron interactions can lead to the emergence of insulating state. These findings underline the intricate correlations between lattice degrees of freedom and SOC in determining the ground state, which effectively stimulate the physical pressure between like structures by chemical compression.
Silicon-air batteries (SABs), a new type of semiconductor air battery, have a high energy density. However, some side reactions in SABs cause Si anodes to be covered by a passivation layer to prevent continuous discharge, and the anode utilization rate is low. In this work, reduced graphene oxide (RGO) fabricated via high-temperature annealing or L-ascorbic acid (L.AA) reduction was first used to obtain Si nanowires/RGO-1000 (Si NWs/RGO-1000) and Si nanowires/RGO-L.AA (Si NWs/RGO-L.AA) composite anodes for SABs. It was found that RGO suppressed the passivation and self-corrosion reactions and that SABs using Si NWs/RGO-L.AA as the anode can discharge for more than 700 h, breaking the previous performance of SABs, and that the specific capacity was increased by 90.8% compared to bare Si. This work provides a new solution for the design of high specific capacity SABs with nanostructures and anode protective layers.
The ultra-high nickel cathode material has important application prospect in power lithium-ion batteries. However, the poor structural stability and serious surface/interfacial side reactions during long cycles severely hinder the material's practical application. In this paper, Cs+ doping and polymethyl methacrylate (PMMA) coating are used to synergistically modify the NCM955 material. The results show that the corresponding discharge specific capacity of NCMCs-2@P-2 material reaches 152.02 mAh/g at 1 C (1 C = 200 mA/g) and 125.66 mAh/g at 5 C after 300 cycles, and the capacity retention is 78.11% and 72.21%, respectively. In addition, it still maintains 156.36 mAh/g discharge specific capacity at 10 C, and these rate and cycle properties exceed those reported on ultra-high nickel cathode material. Moreover, NCMCs-2@P-2 material has higher migration energy barrier of Ni2+ and lower migration energy barrier of Li+ than that of NCM955 material. Therefore, NCMCs-2@P-2 material has excellent electrochemical properties, which has been proved by a series of structural characterization, theoretical calculation and performance test. The synergistic enhancement of Cs+ doping and PMMA coating accelerates lithium ion diffusion kinetics, stabilizes crystal structure, and inhabits surface/interface side reaction.
Flexible zinc-ion batteries (FZIBs) have been acknowledged as a potential cornerstone for the future development of flexible energy storage, yet conventional FZIBs still encounter challenges, particularly concerning performance failure at low temperatures. To address these challenges, a novel anti-freezing leather gel electrolyte (AFLGE-30) is designed, incorporating ethanol as a hydrogen bonding acceptor. The AFLGE-30 demonstrates exceptional frost resistance while maintaining favorable flexibility even at −30 ℃; accordingly, the battery can achieve a high specific capacity of about 70 mAh/g. Cu//Zn battery exhibits remarkable stability at room temperature, retaining ~96% efficiency after 120 plating/stripping cycles at 1 mA/cm2. Concurrently, the Zn//Zn symmetric batteries demonstrate a lifespan of 4100 h at room temperature, which is attributed to the enhancement of Zn2+ deposition kinetics, restraining the formation of zinc dendrites. Furthermore, FZIBs exhibit minimal capacity loss even after bending, impacting, or burning. This work provides a promising strategy for designing low-temperature-resistant FZIBs.
The sluggish reaction kinetics of the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) remain obstacles to the commercial promotion of water splitting and direct methanol fuel cells. Considering the vital role of noble metals in electrocatalytic activity, this work focuses on the rational synthesis of Ni-noble metal composite nanocatalysts for overcoming the drawbacks of high cost and susceptible oxidized surfaces of noble metals. The inherent catalytic activity is improved by the altered electronic structure and effective active sites of the catalyst induced by the size effect of noble metal clusters. In particular, a series of Ni-noble metal nanocomposites are successfully synthesized by partially introducing noble metal into Ni with porous interfacial defects derived from Ni-Al layered double hydroxide (LDH). The Ni10Pd1 nanocomposite exhibits high OER catalytic activity with an overpotential of 0.279 V at 10 mA/cm2, surpassing Ni10Ag1 and Ni10Au1 counterparts. Furthermore, the average diameter of Pd clusters gradually increases from 5.57 nm to 44.44 nm with the increased proportion of doped Pd, leading to the passivation of catalytic activity due to the exacerbated surface oxidation of Pd in the form of Pd2+. After optimization, Ni10Pd1 delivers significantly enhanced OER and MOR electroactivities and long-term stability compared to that of Ni2Pd1, Ni1Pd1 and Ni1Pd2, which is conducive to the effective utilization of Pd and alleviation of surface oxidation.
Sodium metal batteries (SMBs) have drawn much attention as complement to lithium metal batteries for next generation high-energy batteries. However, it is still a big challenge to enhance their cycling stability without sufficient sodium reserve in anode, due to the non-uniform Na plating/stripping and uncontrolled Na dendrite growth. Herein, a dual layer host consists of sodiophilic graphene@antimony nanoparticles bottom layer and 3D polyacrylonitrile nanofiber top layer (PAN-G@Sb) is employed to enable highly reversible Na plating/stripping. Thanks to the uniform Na deposition, PAN-G@Sb delivers an outstanding average Coulombic efficiency of 99.8%, highly reversible Na plating/stripping for 1000 cycles at 2.0 mA/cm2, as well as over 1000 h of stable operation in symmetric cells. When paired with a high mass loading Na3V2(PO4)3 (NVP) cathode (16.2 mg/cm2), the full cell (N/P ratio = 1.4) also displays prominent capacity retention of 98.7% after 250 cycles with a high energy density of 284.6 Wh/kg. Moreover, PAN-G@SbNVP anode-free full cell also shows an excellent capacity retention of 91.0% after 50 cycles at 0.5 C, exhibiting the stable operation of high energy SMBs.
Solid-state batteries (SSBs) with thermal stable solid-state electrolytes (SSEs) show intrinsic capacity and great potential in energy density improvement. SSEs play critical role, however, their low ionic conductivity at room temperature and high brittleness hinder their further development. In this paper, polypropylene (PP)-polyvinylidene fluoride (PVDF)-Li1.3Al0.3Ti1.7(PO4)3 (LATP)-Lithium bis(trifluoromethane sulphonyl)imide (LiTFSI) multi-layered composite solid electrolyte (CSE) is prepared by a simple separator coating strategy. The incorporation of LATP nanoparticle fillers and high concentration LiTFSI not only reduces the crystallinity of PVDF, but also forms a solvation structure, which contributes to high ionic conductivity in a wide temperature. In addition, using a PP separator as the supporting film, the mechanical strength of the electrolyte was improved and the growth of lithium dendrites are effectively inhibited. The results show that the CSE prepared in this paper has a high ionic conductivity of 6.38×10–4 S/cm at room temperature and significantly improves the mechanical properties, the tensile strength reaches 11.02 MPa. The cycle time of Li/Li symmetric cell assembled by CSE at room temperature can exceed 800 h. The Li/LFP full cell can cycle over 800 cycles and the specific capacity of Li/LFP full cell can still reach 120 mAh/g after 800 cycles at 2 C. This CSE has good cycle stability and excellent mechanical strength at room temperature, which provides an effective method to improve the performance of solid electrolytes under moderate condition.
Lithium metal batteries, with their light mass anode and high theoretical specific capacity of 3860 mAh/g, have great potential for development in achieving high energy density. However, the generation of lithium dendrites and the loss of dead lithium pose a serious threat to the safety and long-cycle stability of batteries. Herein, we utilize the Lewis acid-base interaction principle for lithium-ion migration regulation. Through loading solid-acids onto molecular sieves to immobilize Lewis base (PF6−), we achieve accelerated dissociation of lithium salts and successfully increase the lithium ion transference number to 0.44. Lewis acid-base interaction helps lithium metal batteries achieve more uniform lithium deposition, with an average CE improved to 92.8%. The symmetrical cells can be plated/stripped stably for more than 800 h of cycling. Full cell with high surface-loaded LFP cathode (14 mg/cm2) exhibits impressively high capacity retention of 90.7% after 120 cycles at 0.5 C.
Rationally design the morphology and structure of electroactive nanomaterials is an effective approach to enhance the performance of aqueous batteries. Herein, we co-engineered the hollow architecture and interlayer spacing of layered double hydroxides (LDH) to achieve high electrochemical activity. The hierarchical hollow LDH was prepared from bimetallic zeolitic imidazolate frameworks (ZIF) by a facile cation exchange strategy. Zn and Cu elements were selected as the second metals incorporated in Co-ZIF. The characteristics of the corresponding derivatives were studied. Besides, the transformation mechanism of CoZn-ZIF into nanosheet-assembled hollow CoZnNi LDH (denoted as CoZnNi-OH) was systematically investigated. Importantly, the interlayer spacing of CoZnNi-OH expands due to Zn2+ incorporation. The prepared CoZnNi-OH offers large surface area, exposed active sites, and rapid mass transfer/diffusion rate, which lead to a significant enhancement in the specific capacitance, rate performance, and cycle stability of CoZnNi-OH electrode. In addition, the aqueous alkaline CoZnNi-OH//Zn showed a maximum energy density/power density of 0.924 mWh/cm2, 8.479 mW/cm2. This work not only raises an insightful strategy for regulating the morphology and interlayer spacing of LDH, but also provides a reference of designing hollow nickel-based nanomaterials for aqueous batteries.
High-capacity Ni-rich layered cathodes LiNixCoyMn1−x−yO2 (NCM) have been widely recognized as highly promising candidates for lithium-ion batteries (LIBs). However, NCM cathodes are suffered from sluggish Li-ion kinetics and fast capacity decay. Herein, the Nb/Ti co-doping strategy has been proposed by formation energy analysis to enhance the mechanical and chemical integrities of NCM cathode. Nb/Ti co-doping facilitates Li-ion transport of NCM cathode for boosting the rate ability. Furthermore, the structure stability is prominently improved for the stronger Nb–O and Ti–O bonds, resulting from the suppressed sharp contraction of c axis, inhibited microcracks formation, and alleviated electrolyte corrosion. Inspired by the synergistic effect of Nb/Ti co-doping, the modified NCM exhibits superior comprehensive electrochemical performances. The Nb/Ti co-doping NCM exhibits an increased discharge capacity of 144.3 mAh/g at 10 C and an outstanding capacity retention remained 92.7% after 300 cycles at 1 C. This work offers a promising approach to developing high-performance cathode materials.
For realizing the goals of “carbon peak” and “carbon neutrality”, lithium-ion batteries (LIB) with LiFePO4 as the cathode material have been widely applied. However, this has also led to a large number of spent lithium-ion batteries, and the safe disposal of spent lithium-ion batteries is an urgent issue. Currently, the main reason for the capacity decay of LiFePO4 materials is the Li deficiency and the formation of the Fe3+ phase. In order to address this issue, we performed high-temperature calcination of the discarded lithium iron phosphate cathode material in a carbon dioxide environment to reduce or partially remove the carbon coating on its surface. Subsequently, mechanical grinding was conducted to ensure thorough mixing of the lithium source with the discarded lithium iron phosphate. The reaction between CO2 and the carbon coating produced a reducing atmosphere, reducing Fe3+ to Fe2+ and thereby reducing the content of Fe3+. The Fe3+ content in the repaired LiFePO4 material is reduced. The crystal structure of spent LiFePO4 cathode materials was repaired more completely compare with the traditional pretreatment method, and the repaired LiFePO4 material shows good electrochemical performance and cycling stability. Under 0.1 C conditions, the initial capacity can reach 149.1 mAh/g. It can be reintroduced for commercial use.
Urea-assisted water electrolysis offers a promising route to reduce energy consumption for hydrogen production and meanwhile treat urea-rich wastewater. Herein, we devised a shear force-involved polyoxometalate-organic supramolecular self-assembly strategy to fabricate 3D hierarchical porous nanoribbon assembly Mn-VN cardoons. A bimetallic polyoxovanadate (POV) with the inherent structural feature of Mn surrounded by [VO6] octahedrons was introduced to trigger precise Mn incorporation in VN lattice, thereby achieving simultaneous morphology engineering and electronic structure modulation. The lattice contraction of VN caused by Mn incorporation drives electron redistribution. The unique hierarchical architecture with modulated electronic structure that provides more exposed active sites, facilitates mass and charge transfer, and optimizes the associated adsorption behavior. Mn-VN exhibits excellent activity with low overpotentials of 86 mV and 1.346 V at 10 mA/cm2 for hydrogen evolution reaction (HER) and urea oxidation reaction (UOR), respectively. Accordingly, in the two-electrode urea-assisted water electrolyzer utilizing Mn-VN as a bifunctional catalyst, hydrogen production can occur at low voltage (1.456 V@10 mA/cm2), which has the advantages of energy saving and competitive durability over traditional water electrolysis. This work provides a simple and mild route to construct nanostructures and modulate electronic structure for designing high-efficiency electrocatalysts.
In the practical operations of the sodium ion (Na+) batteries (SIBs), the fast transport of Na+ is desired for the rate performance, because the other ions in an electrolyte are electrochemically inert. In this study, we use molecular dynamics simulations to investigate the partial conductivity of Na+ (σNa+) in the salt-in-ionic liquid electrolytes (SILEs) composed of 1-ethyl-3-methylimidazolium (EMIM+) and bis(fluorosulfonyl)imide (FSI−) with various molar fraction of NaFSI. The simulations show that while the ionic conductivity of the SILE decreases monotonically with the increase of salt fraction of NaFSI, σNa+ peaks in the SILE with 0.5 molar fraction of NaFSI. Detailed analyses indicate that with the increase of salt fraction, the coordination structure of FSI− around Na+ changed from bidentate manner to monodentate manner which weakens the binding of FSI− to Na+. The effects are two folds. On one hand, the increased monodentate coordinations cause a large aggregate that hinders the transport of Na+ within the aggregate; on the other hand, the large aggregate captures most FSI− to form percolating ion network, and thus leaves a small portion of Na+’s that are not in the large aggregate to be more "free" to transport in the SILE.
Transition metal selenides are considered promising electrochemical energy storage materials due to their excellent rate properties and high capacity based on multi-step conversion reactions. However, its practical applications are hampered by poor conductivity and large volume variation for Na+ storage, which resulting fast capacity decay. Herein, a facile metal-organic framework (MOF) derived method is explored to embed Cu2-xSe@C particles into a carbon nanobelts matrix. Such carbon encapsulated nanobelts' structural moderate integral electronic conductivity and maintained the structure from collapsing during Na+ insertion/extraction. Furthermore, the porous structure of these nanobelts endows enough void space to mitigate volume stress and provide more diffusion channels for Na+/electrons transporting. Due to the unique structure, these Cu2-xSe@C nanobelts achieved ultra-stable cycling performance (170.7 mAh/g at 1.0 A/g after 1000 cycles) and superior rate capability (94.6 mAh/g at 8 A/g) for sodium-ion batteries. The kinetic analysis reveals that these Cu2-xSe@C nanobelts with considerable pesoudecapactive contribution benefit the rapid sodiation/desodiation. This rational design strategy broadens an avenue for the development of metal selenide materials for energy storage devices.
Nickel-rich cathode materials have received widespread attention due to their high energy density. However, the poor rate capability and inferior cycle stability seriously hinder their large-scale application. The traditional co-precipitation method for preparing them has a long process and easily arises agglomeration leading to inhomogeneous element distribution. Here, a novel precursor containing Li element was prepared by ultrafast spray pyrolysis (SP) in 3–5 s. Then the precursor was used to synthesize pristine LiNi0.9Co0.05Mn0.05O2 (NCM90) and 1% Mg modified LiNi0.9Co0.05Mn0.05O2 (NCM90-Mg1). This method gets rid of mixing Li/Mg source and the precursor prepared by common co-precipitation, thus could achieve homogeneous lithiation and Mg2+ doping. The cell parameter c is expanded, and the cation disorder is reduced after Mg2+ doping. Furthermore, the harmful H2-H3 phase transition in NCM90-Mg1 is also well suppressed. As a result, the obtained NCM90-Mg1 shows better electrochemical performance than NCM90. Within 2.8–4.3 V (25 ℃), the specific discharge capacity of NCM90-Mg1 at 5 C is as high as 169.1 mAh/g, and an outstanding capacity retention of 70.0% (10.0% higher than NCM90) can be obtained after 400 cycles at 0.5 C. At 45 ℃, a capacity retention of 81.9% after 100 cycles at 1 C is recorded for NCM90-Mg1. Moreover, the NCM90-Mg1 also exhibits superior cycle stability when cycled at high cut-off voltage (4.5 V, 25 ℃), possessing the capacity retention of 79.2% after 200 cycles at 1 C. Therefore, SP can be proposed as a powerful method for the preparation of multi-element materials for next-generation high energy density LIBs.
Despite significant progress has been achieved regarding the shuttle-effect of lithium polysulfides, the suppressed specific capacity and retarded redox kinetics under high sulfur loading still threat the actual energy density and power density of lithium-sulfur batteries. In this study, a graham condenser-inspired carbon@WS2 host with coil-in-tube structure was designed and synthesized using anodic aluminum oxide (AAO) membrane with vertically aligned nanopores as template. The vertical array of carbon nanotubes with internal carbon coils not only leads to efficient charge transfer across through the thickness of the cathode, but also provides significant confinement to polysulfide diffusion towards both the lateral and longitudinal directions. Few-layer WS2 in the carbon coils perform a synergistic role in suppressing the shuttle-effect as well as boosting the cathodic kinetics. As a result, high specific capacity (1180 mAh/g at 0.1 C) and long-cycling stability at 0.5 C for 500 cycles has been achieved at 3 mgS/cm2. Impressive areal capacity of 7.4 mAh/cm2 has been demonstrated when the sulfur loading reaches 8.4 mg/cm2. The unique coil-in-tube structure developed in this work provides a new solution for high sulfur loading cathode towards practical lithium-sulfur batteries.
The excited state dynamics and critically regulated factors of reverse intersystem crossing (RISC) in through-space charge transfer (TSCT) molecules have received insufficient attention. Here, five molecules of through space/bond charge transfer inducing thermally activated delayed fluorescence (TADF) are prepared, and their excited state charge transfer processes are studied by ultrafast transient absorption and theoretical calculations. DM-Z has a larger ∆EST, leading to a longer lifetime of intersystem crossing (ISC), resulting in the lowest photoluminescence quantum yield (PLQY). Oppositely, ISC and RISC are demonstrated to take place with shorter lifetimes for TSCT molecules. The face-to-face π-π stacking interactions and electron communication enable DM-B and DM-BX to have an efficient RISC, increasing the weight coefficient of RISC from 1.7% (DM-X) to close to 50% (DM-B and DM-BX) in the solvents, which make DM-BX and DM-B to have a high PLQY. However, partial local excitation in the donor center is observed and the charge transfer is decreased for DM-G and DM-X. The triplet excited state (DM-G) or singlet excited state (DM-X) mainly undergoes inactivation through a non-radiative relaxation process, resulting in less RISC and low PLQY. This work provides theoretical hints to enhance the RISC process in the TADF materials.
TiO2 has been widely studied as one of the most promising anode materials for lithium-ion batteries (LIBs) due to good structural stability and small volume changes. However, its applications are still greatly affected by its poor electrical conductivity. In this work, ultrasmall TiO2 quantum dots (QDs) are firmly grown onto 2D Ti3C2Tx nanosheets (A-TiO2/Ti3C2Tx), benefiting from the positive regulation of (3-aminopropyl)triethoxysilane (APTES). Interestingly, SiO2 nanoparticles produced by the hydrolysis of APTES can strengthen the strong coupling of TiO2 QDs with Ti3C2Tx, thereby enhancing the structural integrity of the composite. As expected, the A-TiO2/Ti3C2Tx composite demonstrates an exceptional lithium storage performance, achieving a high capacity of 425.4 mAh/g for 400 cycles at 0.1 A/g, and an outstanding long-term cycling stability. In-situ electrochemical impedance spectroscopy and theoretical analysis unconver that the superior lithium storage performance is attributed to its unique heterostructure and in-situ N doping derived from APTES, which not only reduces the Li+ adsorption energy, but also gives the fast charge transfer dynamics.
As a kind of emerging energy storage devices, Aqueous zinc ion batteries possess the characteristics of safety, low cost and environmental friendliness. However, their further application is restricted by the sluggish electrochemical reaction kinetics and low conductivity. In this work, we prepare two H3.78V6O13 electrode materials with many active sites, which promotes the kinetics of ion diffusion and then improves the capacity of the cell. The as-obtained HVO-PVP electrode possess a capacity of 393.2 and 285.9 mAh/g at 0.2 and 5.0 A/g, respectively. Moreover, the assembled Zn//HVO-PVP cells also indicate excellent specific capacity and cycle stability at different operating temperatures (0–60 ℃).
Small interfering RNA (siRNA), a promising revolutionary therapy, faces delivery obstacles due to its poor targeting, strong charge negativity and macromolecular nature. Clinical-approved siRNAs can now only be delivered to the liver mediated by the chemically conjugated N-acetylgalactosamine (GalNAc) ligand, the conjugate can be effectively uptaken into cells through interaction with asialoglycoprotein receptor (ASGPR) highly expressed on liver hepatocytes. To further explore an efficient non-hepatic targeted delivery strategy, in this study, we designed a delivery system that chemically conjugated p53 siRNA to renal tubular cell-targeting peptides for targeting the kidney, which was suitable for industrial transformation. Results showed that peptide-siRNA conjugate could specifically enter renal tubular epithelial cells and silence target genes. In cisplatin-induced acute kidney injury (AKI) mice, peptide-siRNA conjugate blocked the p53-mediated apoptotic pathway and alleviated renal damage. The innovative proposed system to conjugate kidney-targeting peptides with siRNA achieved the efficient kidney-targeted delivery of siRNA and provided a prospective choice for treating AKI.
Asperfilasin A (1), featuring a unique 5/5 cyclopenta[c]pyrrol-one bicyclic core, represents a newly discovered skeletal cytochalasan isolated from Aspergillus flavipes. The enantioselective total synthesis was efficiently accomplished from the key intermediate (S)-6 with three contiguous stereocenters in 5 steps and the synthetic 1 induced G2/M-phase cell cycle arrest of HT29 cells and apoptosis of HL60 and NB4 cells by activation of caspase-3 and degradation of PARP. (S)-6, bearing three contiguous chiral centers, was efficiently constructed by a novel Nazarov cyclization reaction containing basic nitrogen, which was less developed, primarily due to the incompatibility of basic nitrogen under acidic reaction conditions. This reaction allows a wide range of pentadienone substrates containing basic nitrogen to undergo Nazarov cyclization in a single regioselective and diastereoselective manner and is capable of generating three stereocenters simultaneously. Furthermore, the mechanism of the Nazarov cyclization and the origin of the regio- and diastereoselectivity were elucidated by DFT calculations and deuteration experiments, providing valuable insights into the reaction and serving as a guide for future applications involving substrates containing basic nitrogen.
Molecularly imprinted polymers (MIPs) are a kind of synthetic receptors possessing wide application prospects in proteins recognition. However, there are still great challenges in proteins imprinting due to their large size and easy conformation change. In this study, we explored epitope-oriented MIP based on host-guest interaction (hg-MIP) and constructed a novel hg-MIP-SERS (surface-enhanced Raman scatting) approach for efficiently recognizing the terminal epitopes of neuron-specific enolase (NSE), a well-known disease biomarker for small cell lung cancer, neuroblstom, and Alzheimer's disease. The C- and N-terminal epitopes of NSE were modified with 4-(phenylazo) benzoic acid, then they were used as the templates and immobilized on β-cyclodextrin-functionalized substrates. The imprinted layer was formed by polymerization of various functional monomers. Combined with SERS detection, an antibody-free sandwich assay based on hg-MIP was successfully used to detect the concentration of NSE in human serums, with the advantages of simple operation, small sample volume (5 µL), wide linear range (1–104 ng/mL) and a limit of detection as low as 0.01 ng/mL. The developed epitope-oriented hg-MIP-SERS approach can also be extended to other proteins, expanding the imprinting method of proteins, and has a broad development space in the field of protein separation and detection.
Proteolysis-targeting chimera (PROTAC) has emerged as an efficient strategy to accurately control intracellular protein levels. However, conventional PROTACs are generally limited by nonspecific protein degradation and off-tissue side effects. Particularly, there is a lack of effective chemical tools for visualizing protein degradation. Herein, a near-infrared fluorescent and theranostic PROTAC (PRO-S-DCM) was designed for imaging the degradation of bromodomain-containing protein 4 (BRD4). PRO-S-DCM could be tumor-specifically activated and exhibited favorable imaging effects both in vitro and in vivo. PRO-S-DCM was proven to be a theranostic probe, which potently inhibited growth, invasion and migration of HeLa cells and induced cell apoptosis.
The potential of metal nanoclusters in biomedical applications is limited due to aggregation-caused quenching (ACQ). In this study, an in situ self-assembled pitaya structure was proposed to obtain stable fluorescence emission through protein coronas-controlled distance between gold nanoclusters (Au NCs). Interestingly, the gold ion complexes coated with proteins of low isoelectric point (pI) nucleate at the secondary structure of proteins with high pI through ionic exchange within cells, generating fluorescent Au NCs. It is worth noting that due to the steric hindrance formed by the protein coronas on the surface of Au NCs, the distance between Au NCs can be controlled, avoiding electron transfer caused by close proximity of Au NCs and inhibiting fluorescence ACQ. This strategy can achieve fluorescence imaging of clinical tissue samples without observable side effects. Therefore, this study proposes a distance-controllable self-assembled pitaya structure to provide a new approach for Au NCs with stable fluorescence.
As PEGylated liposomes have witnessed remarkable advancements in drug delivery, their immunogenicity has emerged as a notable challenge. In this study, we discovered that a simple pre-injection of folic acid (FA) effectively mitigated the immunogenicity of PEGylated liposomes and enhanced their in vivo performance by tolerating splenic marginal zone B cells. FA specifically inhibited the internalization of PEGylated liposomes by splenic marginal zone B cells, thereby reducing splenic lymphocyte proliferation and specific IgM secretion. This modulation alleviated IgM-mediated accelerated blood clearance and adverse accumulation of the PEGylated liposomes in the skin. These findings provide new insights into the immunomodulatory effects of FA and promising avenues to enhance the efficacy and safety of PEGylated liposomal nanomedicines.
Bacterial infection, insufficient angiogenesis, and oxidative damage are generally regarded as key issues that impede wound healing, making it necessary to prepare new biomaterials to simultaneously address these problems. In this work, monodispersed CeO2@CuS nanocomposites (NCs) were successfully prepared with tannin (TA) as the reductant and linker. Due to abundant oxygen vacancies in CeO2 and the polyphenolic structure of TA, the TA-CeO2@CuS NCs exhibited a remarkable antioxidant ability to scavenge excessive reactive oxygen species (ROS), which would likely induce serious inflammation. In addition, the TA-CeO2@CuS NCs demonstrated excellent antibacterial capability with near-infrared ray (NIR) irradiation, and the released copper ions could promote the regeneration of blood vessels. These synergistic effects indicated that the synthesized TA-CeO2@CuS NCs could serve as a promising biomaterial for multimodal wound therapy.
Currently, it is still a challenge to develop an organic photosensitizer (PS) with outstanding near-infrared absorption, low O2 dependence, precise tumor targeting and rapid clearance through the kidney to improve the overall outcome of phototherapy. In this study, we have designed an organic PS (NcPB) with an excellent near-infrared light absorption through a refined molecular strategy. Meanwhile, NcPB was assembled into nanoparticles with different sizes (NanoNcPB-1 and NanoNcPB-0) by a supramolecular modulation strategy. As the results, the nanoparticle with an ultra-small size (NanoNcPB-1) generated a large number of superoxide anion (O2•−) in a low-O2-dependent manner and release plenty of heat. Furthermore, the results of in vivo experiments demonstrated that NanoNcPB-1 actively accumulated in tumor tissues and showed a 92% tumor inhibition after photodynamic and photothermal combination therapy. More importantly, NanoNcPB-1 could be rapidly cleared from the body of mice via the renal pathway, which alleviates potential side effects of prolonged retention of PS in the circulation.
Receptor tyrosine kinases (RTKs) are biological enzymes expressed on cell membranes that can influence cellular signaling, and their overexpression in tumor cells makes them a key route to assess relevant tumor processes. The development of a delivery system that targets and accumulates in RTKs overexpressing-cells at the on-target site is significant for the monitoring of tumor progression and clinical applications through longer tumor site signaling response under low injection frequency. Here, a host-guest nanoscale fluorescent probe SNI@ZIF-8 based on zeolitic imidazolate framework-8 (ZIF-8) and a fluorescent probe SNI constructed from receptor tyrosine kinase inhibitor was proposed and prepared for targeting RTKs and enabling prolonged fluorescence imaging in vivo. The folded conformation of the probe SNI resulted in low background fluorescence, and the unfolding of the SNI conformation upon insertion of the RTKs active pocket showed significant fluorescence enhancement thus enabling real-time detection of RTKs. The host-guest system SNI@ZIF-8 could release guest molecules due to the presence of the enzyme, emphasizing the reporting of stable fluorescent signals over time under low injection frequency. SNI@ZIF-8 could provide a signal response on the cell membrane of RTKs overexpressing cells without interference from other substances, and provided a longer fluorescent signal than SNI at equivalent number of injections in tumor-bearing mice. The host-guest system SNI@ZIF-8, with its obvious tumor site enrichment ability and clear fluorescence imaging ability, could be successfully applied to the detection of RTKs on cell membranes in biological systems, providing a new strategy for determining the process of tumor development in clinical applications.
Breath analysis can be used to diagnose diseases non-invasively. Accurate measurement of volatolomics is critical for breath analysis to be a gold standard. Tedlar bags (TB) are often used to collect breath samples, but they emit contaminants that affect accuracy. This issue was overlooked in previous studies. We found contamination issues with TB (e.g., siloxanes and aromatic impurities) that affect the identification of volatile organic compounds (VOCs) due to impurities. Then, home-designed equipment (HD) made with poly-tetrafluoride (PTFE) and quartz glass for breath collection was developed and employed in clinical trials. 15 healthy individuals and 32 non-small cell lung cancer (NSCLC) patients at IA stage participated in this study. 610 VOCs can be collected through TB, which is less than HD (1109 VOCs), demonstrating that the inner wall of the TB easily adsorbs VOCs, leading to decreased detection concentrations. Otherwise, utilizing orthogonal partial least squares discriminant analysis (OPLS-DA), we identified chemical markers with significant discriminatory power (VIP > 1.5, P < 0.05). The HD method identified 12 target VOCs, surpassing the 3 target VOCs discerned by the TB method. A model combined with a machine learning algorithm for distinguishing early-stage lung cancer patients was established based on biomarkers, which were selected based on OPLS-DA. The results showed strong predictive capabilities for the HD-based model. It indicated that 12 biomarkers derived from the HD model were more effective in distinguishing NSCLC patients, with an AUC value of 0.92, compared to the AUC value of 0.5 from 3 markers obtained from the TB model. The sensitivity and specificity in the confusion matrix reached 100% and 80% for the HD test, but TB test reached only 40% and 60%. This work demonstrated that optimizing and standardizing VOCs collection methodology from breath of lung cancer patients is essential to identify actual volatiles, which could promote disease volatolomics worldwide.
Electrocatalytic water splitting for hydrogen production is a key approach to tackling the current energy crisis. Among the catalysts, the traditional Pd@C catalysts are remarkable for their efficiency in hydrogen evolution. However, the high cost and scarcity of Pd catalysts, as well as the instability caused by the corrosiveness of carbon-based substrates, hinder their large-scale application. To overcome this challenge, an effective strategy is to construct highly dispersed Pd single atoms to improve palladium utilization and choose more stable materials as supports. In this study, TiO2−x carriers with abundant oxygen vacancies were prepared and loaded with Pd by photoreduction deposition. Adjusting the palladium content resulted in three forms of Pd-loaded TiO2−x: nanoparticles (Pd@TiO2−x(6%, 10%)), nanoclusters (Pd@TiO2−x(3%)) and single atoms (Pd@TiO2−x(1.5%)). The oxygen vacancies improved the stability of the titanium dioxide materials by providing more active hydrogen adsorption sites and increasing the affinity of Pd for active hydrogen. Single atom loading increased the frequency of oxygen holes in the support and the high activity of monatomic Pd promoted the adsorption of active hydrogen and facilitated the formation of active hydrogen intermediates. The synergistic effect of single atoms and oxygen vacancies improved the stability and catalytic activity of the composite material. Pd@TiO2−x(1.5%) showed outstanding performance in hydrogen evolution in an acidic medium with an overpotential of only 24 mV at a current density of 10 mA/cm2 and a low Tafel rise of 41.9 mV/dec. This study provides an effective strategy for the development of high-performance hydrogen evolution (HER) catalysts.
The efficacy of photodynamic therapy (PDT) for breast tumors is hindered by challenges such as inadequate tumor targeting, limited treatment depth, and strong oxygen dependence. Herein, a promising photosensitizer VP-B was developed to simultaneously address all the aforementioned issues for the treatment of hypoxic deep-seated breast tumors. The biotinylated photosensitizer VP-B not only exhibited precise targeting towards breast tumor tissue, but also efficiently triggered the generation of abundant 1O2 and O2−• under 690 nm red light irradiation. Indeed, the red light penetration ability enabled VP-B to achieve successful application in a mouse orthotopic breast tumor model. After intravenous administration, VP-B can selectively target tumor tissues and significantly inhibit the growth of hypoxic deep-seated tumors. Therefore, this new type Ⅰ & Ⅱ photosensitizer could boost fluorescence-guided photodynamic therapy of other hypoxic solid tumors.
Venetoclax (Vene), a BCL-2 inhibitor, is widely used as a chemotherapeutic drug in acute myeloid leukemia (AML). However, its treatment specificity for leukemia cells is limited, often leading to side effects and treatment resistance. In this study, we utilized l-phenylalanine as an efficient nanocarrier to enhance the delivery of Vene, forming the complex Vene@8P6. This complex was then applied to AML mouse models and human AML cell lines. The in vitro analysis showed that THP-1 and HL60 cells rapidly absorbed the Vene@8P6 nanoparticles. This absorption resulted in severe DNA damage, increased reactive oxygen species (ROS) production, elevated apoptosis rates, and decreased cell proliferation compared to the administration of Vene alone. In vivo studies demonstrated that Vene@8P6 more efficiently targeted leukemia cells than normal hematopoietic cells within the bone marrow and other major organs in AML mice, as evidenced by bioluminescence imaging and flow cytometry analysis. Furthermore, Vene@8P6 treatment resulted in reduced drug side effects and improved therapeutic efficacy in AML mice. Overall, Vene@8P6 represents a novel and efficient therapeutic agent for AML, offering enhanced leukemia target specificity, reduced side effects, and improved treatment outcomes.
Programmed cell death protein 1/programmed cell death 1 ligand 1(PD-1/PD-L1) protein-protein interaction represents an appealing target for cancer therapy. Several antibody drugs have been developed to target this interaction, but they are less effective in the treatment of melanoma. To overcome the limitations, the first proteolysis-targeting chimeric (PROTAC) small molecules simultaneously targeting PD-L1 and Src homology phosphotyrosyl phosphatase 2 (SHP2) were designed. By employment of PD-1/PD-L1 inhibitors BMS01 or BMS-37, SHP2 inhibitor SHP099 and E3 ligase ligands, a series of potent PD-L1 and SHP2 dual PROTACs were synthesized. The most promising compounds BS-7C-V2 and BS327V2 efficiently induced PD-L1 and SHP2 degradation and demonstrated significantly improved immune potency in B16-F10 and A375 cell lines. More importantly, the efficacy of BS-7C-V2 and BS327V2 in a B16-F10 transplanted mouse model was further evaluated based on their degradation ability in vivo. Taken together, our work qualifies the new dual PROTACs as a potent degrader of PD-L1 and SHP2. The biological and mechanism investigations with BS-7C-V2 and BS327V2 prove that dual PROTACs can play an anti-tumor role in vivo and in vitro, and can provide a new therapeutic strategy for melanoma.
H2O2 is an environmentally friendly oxidizing agent with minimal secondary pollution; however, its application has always been constrained by factors such as storage and transportation. In this study, we propose an innovative method for storing and releasing H2O2 using hydrogels. Commercial hydrogels (sodium polyacrylate) can undergo swelling and absorb H2O2 in aqueous solutions, and the swollen hydrogel can continuously release H2O2 under osmotic pressure. And the characteristics of osmotic pressure drive ensure the recyclability of hydrogel for H2O2 storage. Experimental results demonstrate that H2O2 can stably exist within the hydrogel for an extended period, and this strategy helps to avoid explosion the risk and potential environmental hazards during the transportation of H2O2. Finally, experiments confirm that the hydrogel controlled sustained release of H2O2 is effective in both Fenton reactions and the process of bacterial inactivation. This work introduces new ideas for the storage of H2O2, and the sustained release of H2O2 may have significant implications in the fields of healthcare, environmental science, catalysis, and beyond.
Although the powder Fenton-like catalysts have exhibited high catalytic performances towards pollutant degradation, they cannot be directly used for Fenton-like industrialization considering the problems of loss and recovery. Therefore, the membrane fixation of catalyst is an important step to realize the actual application of Fenton-like catalysts. In this work, an efficient catalyst was developed with Co-Nx configuration facilely reconstructed on the surface of Co3O4 (Co-Nx/Co3O4), which exhibited superior catalytic activity. We further fixed the highly efficient Co-Nx/Co3O4 onto three kinds of organic membranes and one kind of inorganic ceramic membrane installing with the residual PMS treatment device to investigate its catalytic stability and sustainability. Results indicated that the inorganic ceramic membrane (CM) can achieve high water flux of 710 L m-2 h-1, and the similar water flux can be achieved by Co-Nx/Co3O4/CM even without the pressure extraction. We also employed the Co-Nx/Co3O4/CM system to the wastewater secondary effluent, and the pollutant in complicated secondary effluent could be highly removed by the Co-Nx/Co3O4/CM system. This paper provides a new point of view for the application of metal-based catalysts with M-Nx coordination in catalytic reaction device.
Although diverse signal-amplified methods have been committed to improve the sensitivity of surface plasmon resonance (SPR) biosensing, introducing convenient and robust signal amplification strategy into SPR biosensing remains challenging. Here, a novel nanozyme-triggered polymerization amplification strategy was proposed for constructing highly sensitive surface plasmon resonance (SPR) immunosensor. In detail, Au@Pd core-shell nanooctahedra nanozyme with superior peroxidase (POD)-like activity was synthesized and utilized as a label probe. Simultaneously, Au@Pd core-shell nanooctahedra nanozyme can catalyze the decomposition of H2O2 to form hydroxyl radicals (•OH) that triggers the polymerization of aniline to form polyaniline attaching on the surface of sensor chip, significantly amplifying SPR responses. The sensitivity of SPR immunosensor was enhanced by nanozyme-triggered polymerization amplification strategy. Using human immunoglobulin G (HIgG) as a model, the constructed SPR immunosensor obtains a wide linear range of 0.005–1.0 µg/mL with low detection limit of 0.106 ng/mL. This research provides new sights on establishing sensitive SPR immunosensor and may evokes more inspiration for developing signal amplification methods based on nanozyme in biosensing.
Invasive fibroblast-like synoviocytes (FLS), inflammatory macrophages and osteoclasts are the main three contributors to rheumatoid arthritis (RA) progression by promoting synovial inflammation and destructing cartilage and bone. Targeting these three cell types for restoring the inflammatory homeostasis microenvironment may be a promising anti-RA strategy. Herein, we prepared a reactive oxygen species (ROS)-responsive micelles (DPTM) to co-load dexamethasone (DEX) and pristimerin (PRI) for RA therapy. This ROS-responsive system exhibits the following advantages: (1) It makes use of the "ELVIS" effect for passive delivery and targeting the ROS environment of RA-related cells to rapidly release the payload drugs DEX and PRI. (2) Compared with free drugs, DPTM showed stronger effect on the inhibition of RA-FLS proliferation and the promotion of RA-FLS apoptosis. Moreover, DPTM could significantly weaken the migration ability of RA-FLS as indicated by the results of wound healing assay and transwell assay. (3) DPTM exerted stronger cellular uptake and anti-inflammatory effect in M1 macrophages. (4) In the model studying receptor activator of nuclear factor kappa-B ligand (RANKL)-induced differentiation of bone marrow-derived macrophages (BMDMs) to osteoclasts, DPTM showed a stronger inhibitory activity on osteoclast formation as compared to free drugs. Taken together, these results highlighted the potential of DPTM for targeted RA therapy via inhibition of RA-FLS abnormal activation, macrophage polarization and osteoclastogenesis.
The significance of axial chiral compounds in asymmetric organic catalysis, functional materials, and pharmaceutical useful molecules has encouraged advancements in the atroposelective synthesis of such compounds. Herein, we report the first atroposelective construction of axially chiral N-aryl benzimidazoles catalyzed by a polymer-supported chiral phosphoric acid. A varied library of atropisomers has been synthesized in 30%-96% yield with 58%-98% enantiomeric excess (ee) under a straightforward reaction setup (without the use of molecular sieves). Notably, even after 12 cycles, the immobilized catalyst maintained its reactivity and selectivity (TON > 540).
Benziodazole-triflate, as a novel heterocyclic hypervalent iodine(Ⅲ) reagent, was prepared from the reaction of hypervalent chloroiodine(Ⅲ) with silver triflate under mild conditions. The structure of this new reagent was elucidated by NMR spectroscopy and X-ray crystallography, and its reactions with diverse α-electron withdrawing group substituted carbonyl compounds were investigated. The results implied that benziodazole-triflate could be selectively used as both a 2-iodobenzamido-transfer reagent for the synthesis of oxazole compounds, and a triflate-transfer reagent for the triflation of β-keto-sulfones. Ionic mechanistic pathways, supported by density functional theory (DFT) calculations, were proposed to account for the divergent selectivities of the transformations.
Regioselevtive functionalization of perylene diimides (PDIs) at bay area often requires multistep synthesis and strenuous recrystallization. Direct bromination of perylene diimides only afford the 1, 6 and 1, 7-regioisomers. More importantly, the 1, 6-dibromo regioisomers could only be separated by preparative HPLC. Herein, we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives. This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs, which yields exclusively the 1, 6-regioisomers. Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer, which causes substantial changes on the optoelectronic properties. Moreover, the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm2 V−1 s−1, showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.
Fluorescence imaging-guided photodynamic therapy holds great promise for application in precise cancer diagnosis and treatment, which has motivated high requirements for phototheranostic agents. However, current photosensitizers (PSs) generally face limitations such as short emission wavelength and inadequate reactive oxygen species (ROS) production. Aggregation-caused quenching issue also hinders the phototheranostic efficiency of PSs. Herein, the π-bridge modulation strategy is proposed to construct ionic PSs with enhanced bioimaging and therapeutic outcomes. Two donor-π-acceptor (D-π-A) molecules TPCPY and TFCPY were obtained by incorporating phenyl and furan units as π-bridge, respectively. Both PSs feature aggregation-induced near-infrared emission. Under light irradiation, TPCPY and TFCPY can produce both type Ⅰ and Ⅱ ROS. Introducing furan ring in TFCPY enhances the ROS generation capacity by type Ⅰ photosensitization process, which is consistent with the reduced energy gap between singlet and triplet states from theoretical calculation. Furthermore, TFCPY can achieve quick cellular uptake, accumulate in mitochondria, and then efficiently kill cancer cells, which is superior to TPCPY. Consequently, TFCPY exhibited good antitumor outcomes and excellent in vivo fluorescence imaging ability. This work provides an efficient molecular engineering of introducing heterocycles into the D-π-A skeleton to develop high-performance PSs with both type Ⅰ and Ⅱ ROS generation.
Carbon dots (CDs)-based composites have shown impressive performance in fields of information encryption and sensing, however, a great challenge is to simultaneously implement multi-mode luminescence and room-temperature phosphorescence (RTP) detection in single system due to the formidable synthesis. Herein, a multifunctional composite of Eu&CDs@pRHO has been designed by co-assembly strategy and prepared via a facile calcination and impregnation treatment. Eu&CDs@pRHO exhibits intense fluorescence (FL) and RTP coming from two individual luminous centers, Eu3+ in the free pores and CDs in the interrupted structure of RHO zeolite. Unique four-mode color outputs including pink (Eu3+, ex. 254 nm), light violet (CDs, ex. 365 nm), blue (CDs, 254 nm off), and green (CDs, 365 nm off) could be realized, on the basis of it, a preliminary application of advanced information encoding has been demonstrated. Given the free pores of matrix and stable RTP in water of confined CDs, a visual RTP detection of Fe3+ ions is achieved with the detection limit as low as 9.8 µmol/L. This work has opened up a new perspective for the strategic amalgamation of luminous guests with porous zeolite to construct the advanced functional materials.
Electrochemical nitrate reduction (NO3RR) offers a promising avenue for treating nitrate-contaminated water and recovering ammonia (NH3), yet the complexities of direct electron transfer (DET) and hydrogen atom transfer (HAT) mechanisms crucial for efficiency remain elusive. This study bridges the gap with a combined experimental and theoretical approach, elucidating the impact of catalyst structure on NO3RR pathways. We discover that catalysts favoring strong NO3− adsorption and efficient water dissociation were more inclined towards DET, enhancing denitrification. The Fe@Fe3O4/FF cathode, leveraging the synergistic interplay between metallic Fe and Fe3O4, excelled in NO3RR via DET, achieving an NH3 yield of 0.28 mmol h−1 cm−2 and a Faradaic efficiency of 95.7% for NH3 at -1.6 V (vs. SCE), with minimal nitrite accumulation at 100 mmol/L nitrate. Conversely, the Fe/FF and Fe3O4/CC cathodes showed reduced NH3 production and increased nitrite levels, attributed to the lack of Fe3O4 and metallic Fe, respectively, resulting in a dominant HAT mechanism. Moreover, Fe@Fe3O4/FF facilitated complete denitrification in real wastewater treatment by harnessing Cl− for electrochemically mediated breakpoint chlorination. This research not only deepens our understanding of NO3RR mechanisms but also paves the way for designing superior nitrate reduction catalysts.
Studies widely acknowledge the enhancement of permanganate (Mn(Ⅶ)) oxidation of organic contaminants by coexisting matrices in water. This study investigated the positive influence of Mn(Ⅱ), a common soluble metal ion, on the removal of trace organic pollutants by Mn(Ⅶ). Results showed that introducing 20 µmol/L Mn(Ⅱ) at pH 5.0 accelerated trace organic pollutant removal by promoting colloidal MnO2 formation. UV−vis spectrum, quenching, and probe experiments confirmed role of MnO2 in sulfamethoxazole (SMX) oxidation, with Mn(Ⅲ) playing a predominant role. Meanwhile, in situ-generated MnO2 facilitated Mn(Ⅶ)* formation, enhancing oxidation performance, as indicated by Raman spectroscopy and electrochemical analysis. Eleven transformation products (TPs) of SMX in the Mn(Ⅶ)/Mn(Ⅱ) process were detected by UPLC-QTOF-MS/MS. Subsequently, the reaction pathways of SMX were elucidated through Fukui index analysis and the identification of TPs. Additionally, toxicity simulations with Toxicity Estimation Software Tool (T.E.S.T.) software revealed significantly lower cytotoxicity of TPs of SMX compared to the parent compound. This study unveils an effective strategy to enhance Mn(Ⅶ)-mediated degradation of organic pollutants in water, elucidating Mn(Ⅱ)-induced Mn(Ⅶ) activation mechanisms.
Metal halide perovskite nanocrystals (MHP NCs) are of great candidates in photocatalytic applications due to their extreme light utilization efficiency. However, the instability towards humid environment severely restrict their practical application. Herein, the CsPbBr3/CsPb2Br5 heteronanocrystals (HNCs) were successfully encapsulated into ZIF-8 through a thermal injection method via controlling the molar ratio of Cs+/Pb2+. The surface of ZIF-8 was then modified with hydrophobic copolymer of poly(methyl methacrylate) (PMMA) to improve the water stability. Benefiting from the intimate interfacial interaction and staggered energy band structure, the type-Ⅱ heterojunction of CsPbBr3/CsPb2Br5 guarantees efficient separation and migration of photogenerated electron/hole pairs. Meanwhile, the formation of Z-scheme heterojunction between ZIF-8 and CsPbBr3/CsPb2Br5 HNCs contributes to the adsorption and enrichment of pollutants, further accelerates the photocatalytic antibiotic degradation efficiency towards tetracycline hydrochloride (TCH) in aqueous solution. Nearly 87% of TCH (40 mg/L, 50 mL) was degraded by 40 mg catalyst within 100 min. This work offers a feasible approach in assembling high-performance MHP NCs-based efficient photocatalyst with expanding application in aqueous solution.
In the fight against bacterial infections, it is critical to effectively disrupt biofilms. However, disruption of biofilms becomes exceptionally difficult due to the low permeability of therapeutic agents. Herein, we present a self-propelled nanovesicle (PCL-PLG@CHX) strategy for eliminating biofilms and further expediting the healing of wounds. PCL-PLG@CHX is synthesized by assembling vesicles from amphiphilic polymers, which incorporate both poly-ε-caprolactone and guanidinated-poly-ε-lysine (PCL-PLG) and are infused with chlorhexidine (CHX). Upon application to sites of bacterial infection, PCL-PLG@CHX, abundant in guanidinium structures, effectively accumulates on the negatively charged surface of biofilms. It interacts with reactive oxygen species (ROS) within the biofilm, leading to nitric oxide (NO) production. The generated NO cannot only propel the nanovesicle to penetrate deeper into the biofilm, but also act as a signaling molecule to disperse the biofilm, working in conjunction with the subsequent release of CHX for an enhanced antibacterial impact. Following the eradication of bacteria, the residual guanidine component continues to produce small quantities of NO, facilitating angiogenesis and epithelial growth, thereby accelerating the healing of wounds. Together, our study shows that PCL-PLG@CHX utilizes the potential of guanidine moieties to efficiently break down biofilms and support tissue restoration, tackling the pivotal challenge of biofilm-related diseases.
A novel organocatalytic asymmetric approach to oxazoline derivatives that proceeds through Mannich/annulation reaction of N-acylimines with 3-chlorooxindoles is presented. This strategy provides an efficient and convenient method to access enantioenriched oxazolines such as valuable chiral S, N-oxazoline ligand as well as Ferrox ligand in high yields with excellent enantio– and diastereroselectivity. Furthermore, the optically active oxazoline products can be converted to valuable 1, 2-amino alcohols. More importantly, the synthetic utility of this transformation is demonstrated in the expeditious assembly of chiral Phox-type ligand, which shows excellent catalytic activities.
Herein, we report the design and synthesis of alternating donor-acceptor nanorings [3]C-NA and [4]C-NA, along with a reference linear molecule [3]L-NA, via electrochemical oxidation-induced reductive elimination of alkynyl platinum(Ⅱ) complexes. Unlike [3]L-NA, which exhibits charge defects at its end-groups, the cyclic structures of [3]C-NA and [4]C-NA facilitate enhanced electron delocalization, enabling efficient charge transfer in low-polarity toluene. In the polar solvent dichloromethane (DCM), the increased flexibility of [4]C-NA promotes intramolecular charge transfer and suppresses charge recombination. The observed faster intramolecular charge transfer and slower charge recombination rates in these nanoring acceptor materials suggest their potential for improving the power conversion efficiency of organic solar cells, providing valuable insights for the design of nanoring acceptor materials.
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is an attractive technology for the visualization of metabolite distributions in tissues. However, detection and identification of low-abundance or poorly ionized metabolites remains challenging. Although on-tissue chemical derivatization (OTCD) holds great promise for improving MALDI MS detection sensitivity and selectivity by modification of specific chemical groups, the available methods for subsequent metabolite annotation are limited. Herein, a laser-assisted chemical transfer (LACT)-based parallel OTCD strategy was established for visualizing and annotating carbonyl metabolites in murine brain tissues. Girard's T and Girard's P reagents were applied for parallel OTCD to generate the characteristic m/z pairs with a 19.969 Da mass shift (±0.020 Da tolerance) for rapid recognition of derivatized metabolites. The similarity of spatial distribution patterns of each m/z pair was further statistically evaluated to remove the ambiguous annotations due to the occurrence of interference compounds. As a result, 90 ion pairs were annotated as candidate carbonyl metabolites, 66 were previously known and 24 were potential unreported carbonyls. Furthermore, the spatial alterations of carbonyl metabolites in the ischemic rat brain were successfully visualized and characterized, including small molecule aldehydes and ketones, long-chain fatty aldehydes, and monosaccharides. This further emphasizes great potential of parallel OTCD strategy for efficient and confident molecular annotation of spatial submetabolomics data associated with brain diseases.
Degradation of nitrobenzene (NB) via Fenton-like reaction is considered as an efficient approach for contaminated groundwater remediation. However, the poor stability of H2O2 limits the application of traditional Fenton reactions in soil and groundwater due to the transportation risks of H2O2. In this study, we synthesized a controlled release nano calcium peroxide (nCP) by coating it with polydopamine (PDA) as a solid H2O2 to construct a Fe(Ⅱ)/PDA@nCP Fenton-like system for contaminants degradation. The phenol-quinone transformations of catechol groups on the PDA surface facilitated the Fe(Ⅱ)/Fe(Ⅲ) cycle, resulting in enhanced generation of hydroxyl radicals (HO) and effective long-term degradation of NB. Moreover, the PDA shell modulated the nCP decomposition rate and inhibited sharp pH fluctuations, and the NB removal efficiency was achieved up to 96.8% at pH ranging from 3.0 to 9.0. This study demonstrated the promising application potential of PDA@nCP as a solid-controlled release H2O2 source in Fenton-like system for groundwater contamination remediation.
Pure organic materials with ultralong room-temperature phosphorescence (RTP) and persistent luminescence in broad color gamut exhibit tremendous potential and broad application prospects due to their unique optical properties. This article proposes a simple strategy, polyatomic synergistic effect, to endow persistent luminescent materials with ultralong lifetime and broad color-tunability through polyatomic synergistic effect and non-traditional phosphorescence resonance energy transfer (PRET). By leveraging the polyatomic synergistic effect to enhance the intersystem crossing (ISC) in bibenzimidazole (BBI) derivatives and suppress the non-radiative transition process, ultralong persistent room-temperature phosphorescence has been successfully achieved after incorporating BBI-Cl-M into poly(methyl methacrylate) (PMMA) to form a rigid matrix(BBI-Cl-M@PMMA). Specifically, the ester functionalized bibenzimidazole with modified chlorine on molecular skeleton (BBI-Cl-M) demonstrates a remarkable phosphorescent lifetime (τp) of up to 256.4 ms. In addition, the behaviors and mechanism of RTP via polyatomic synergistic effect have been further understood by theoretical calculation and single crystal analysis. Subsequently, utilizing BBI-Cl-M as the energy donor and Rhodamine B (RB) as the energy acceptor, persistent and multicolor organic afterglow covering from green to red has been realized successfully by simply regulating the doping composition and concentration of PRET systems. These RTP materials have also been applied in underwater afterglow emission and multilevel anti-counterfeiting technology successfully.
Intracellular bacteria (ICB), cloaked by the protective barriers of host cells, pose a formidable challenge to selective and efficient eradication. The employment of activatable photosensitizers based antibacterial photodynamic therapy (aPDT) holds significant potential for selective imaging and photo-inactivation of ICB while minimizing side effects on normal cells. Drawing inspiration from the elevated hypochlorous acid (HClO) levels in ICB infected phagocytes, herein we firstly designed and synthesized a series of HClO-responsive dinuclear Ru(Ⅱ) complexes (Ru1-Ru3) to achieve such a goal. Initially, the luminescence, 1O2 generation and aPDT activity of these Ru(Ⅱ) complexes were suppressed due to the quenching effect of the azo group, but were recovered after reaction with HClO in solutions or within ICB infected phagocytes. The detailed results revealed that Ru1 and Ru3 could not only selectively visualize ICB, but also demonstrated remarkable aPDT activity against ICB, surpassing vancomycin both in vitro and in vivo.
The asymmetric conjugate additions of aryl Grignard reagents to trisubstituted enones by chiral P, N ligand L6 with low catalyst loading (0.25–1.0 mol%) are disclosed. Chiral 2-ester chromanone and its analogs bearing a quaternary stereogenic centers at C2 position were produced in high to excellent yields, enantioselectivities and high turnover number. The notable features of this reaction include its broad substrate scope, complete 1, 4-addition regioselectivities, applicability to both batch and flow for large scale synthesis. This report develops an efficient strategy to apply aryl Grignard reagents in asymmetric 1, 4-conjugation reactions and provides a direct method to incorporate quaternary chiral centers toward the synthesis of biologically relevant chromanone derivatives.
2, 6-Diisopropylaniline reacts with an open-cage fullerene derivative with a 11-membered orifice and forms an open-cage derivative containing one imino group on the rim of the expanded orifice. Further treatment with Lewis acids leads to open-cage fullerenes with an 18-membered orifice. Instead of the direct addition process observed before for less bulky anilines, an electron transfer process takes place in the initial step in the present reaction with bulky 2, 6-diisopropylaniline. As a result, the chemo-selectivity is completely different affording the mono imino open-cage derivative selectively.
Photoredox-mediated reversible-deactivation radical polymerization (RDRP) is an effective approach to synthesize polymers with defined composition and architecture. Current photoinduced RDRP primarily depends on outer-sphere electron transfer or homolysis mechanisms. Herein, we describe an example of iodine-mediated RDRP facilitated by photoinduced charge transfer complex (CTC) catalysis. The approach uses cheap and easily accessible N-heterocyclic nitrenium salt (NHN+···I-) as the photoactive CTC. Upon the irradiation of visible light, NHN+···I- undergoes single electron transfer to generate NHN• and I• radicals. The NHN• radical activates dormant Pn-I polymers via inner-sphere single electron transfer, leading to the propagating Pn• radical for chain growth and the I- anion for recovering the CTC, and the I• radical deactivates the polymerization via coupling with Pn•.
Halide solid-state electrolytes (HSSEs) with excellent ionic conductivity and high voltage stability are promising for all-solid-state Li-ion batteries (ASSLBs). However, they suffer from poor processability, mechanical durability and humidity stability, hindering their large-scale applications. Here, we introduce a dry-processing fibrillation strategy using hydrophobic polytetrafluoroethylene (PTFE) binder to encapsulate Li3InCl6 (LIC) particles (the most representative HSSE). By manipulating the fibrillating process, only 0.5 wt% PTFE is sufficient to prepare free-standing LIC-PTFE (LIC-P) HSSEs. Additionally, LIC-P demonstrates excellent mechanical durability and humidity resistance. They can maintain their shapes after being exposed to humid atmosphere for 30 min, meanwhile still exhibit high ionic conductivity of > 0.2 mS/cm at 25 ℃. Consequently, the LIC-P-based ASSLBs deliver a high specific capacity of 126.6 mAh/g at 0.1 C and long cyclability of 200 cycles at 0.2 C. More importantly, the ASSLBs using moisture-exposed LIC-P can still operate properly by exhibiting a high capacity-retention of 87.7% after 100 cycles under 0.2 C. Furthermore, for the first time, we unravel the LIC interfacial morphology evolution upon cycling because the good mechanical durability enables a facile separation of LIC-P from ASSLBs after testing.
Chemotherapy is the cornerstone of cancer treatment, and paclitaxel (PTX), as a first-line broad-spectrum chemotherapy drug, is widely used in the treatment of multiple tumors in the clinic. However, unsatisfactory efficacy and drug resistance of single chemotherapy have severely hampered the clinical progress of PTX. Herein, three-in-one naringenin (NAR)-loaded PTX polymer prodrug micelles were constructed for efficient and synergistic antitumor therapy. Firstly, the polymer prodrug micelles could simultaneously act as nanoreservoirs for two hydrophobic drugs, PTX and NAR. Secondly, the polymer prodrug micelles enabled dual-responsive intelligent release of PTX and NAR triggered by reduction and acid. Finally, released PTX and NAR exerted synergistic antitumor effects for reversing tumor resistance, while NAR enhanced the immune and anti-inflammatory functions of polymer prodrug micelles. Due to the cascade-enhanced chemotherapeutic augmentation, the intelligent-responsive nanoreservoir proved to be an excellent antitumor therapeutic platform. This work was of great interest for designing superior chemotherapeutic augmentation regimens.
A porous lanthanum (La) carbonate-carbon composite (LaCC) was prepared by vacuum-freeze-drying and pyrolysis techniques to remove phosphorus (P) from wastewater. Using polyethylene glycol as a carbon skeleton template, and the organic ligands are removed during pyrolysis, resulting in the creation of many pore structures. The LaCC showed excellent P removal performance and selectivity over a wide pH range (3–10). It exhibited a rapid adsorption rate and could hold up to 119.5 mg P/g. Fixed-bed column experiments showed that under dynamic conditions, just 1 g of LaCC effectively treated 60 L of P-contaminated wastewater with an initial concentration of 2 mg/L, meeting the primary discharge standard of <0.5 mg/L according to the comprehensive sewage guidelines of China. Bacterial experiments showed that the LaCC could inhibit the growth of Escherichia coli, indicating that it has both P removal and bacterial inhibition effects, which can greatly improve the application range of adsorbents.
Electrocatalytic nitrate reduction reaction (NO3−RR) is a green and competitive method for removing nitrate from water, requiring highly active and long-term stable electrocatalysts. In this work, we report a Cu0 nanorod catalyst with disordered structure (re-Cu NRs), prepared by electrochemical in situ reconfiguration of copper-based nitrides (Cu3N NRs). The amorphous structure allows the exposure of abundant active sites to enhance the electrocatalytic activity because of the disordered atomic arrangement. At a potential of −1.2 V vs. Ag/AgCl, the re-Cu NRs catalyst achieved nearly 100% nitrate conversion within 120 min at a low nitrate concentration (50 mg/L), without the accumulation of nitrite. In-situ DEMS detection reveals that the NO3−RR on re-Cu NRs followed the pathway of *NO3−→ *NO2−→ *NO → *N → *NH → *NH2 → *NH3. Furthermore, combining this proposed pathway with electrochlorination could efficiently transform ammonia into harmless N2 (~99.41%). Theoretical calculations confirm that the amorphous structure on the surface of re-Cu NRs catalysts can facilitate strongly adsorbed nitrate, weaken the rate-determining step of *NH3 → NH3, and suppress hydrogen evolution reaction (HER). This study provides a new approach for designing efficient and stable amorphous catalysts for electrocatalytic nitrate reduction.
Mitochondria are crucial organelles responsible for maintaining cell growth, and their homeostasis is closely linked to pH regulation. Physiologically, mitochondria exhibit a weakly alkaline state (pH~8.0). However, when subjected to stress stimuli that cause damage, cells initiate the process of mitophagy, resulting in mitochondrial acidification. Therefore, monitoring changes in mitochondrial pH to comprehend the physiological processes associated with mitophagy is essential. In this study, we developed an asymmetric pentamethine cyanine dye Cy5.5-H-CyN as a probe for continuous monitoring of mitophagy in living cells. By incorporating an azaindole structure into the dye molecule, a ratiometric fluorescence response was achieved that is specifically responsive to pH variations while preserving its ability to target mitochondria and emit near-infrared fluorescence. Through various methods inducing mitophagy, Cy5.5-H-CyN was employed to determine mitochondrial pH quantitatively, demonstrating its suitability as an ideal probe for continuous monitoring of mitophagy in living cells.
A novel photocatalytic energy transfer-driven radical relay strategy has been introduced for the chemo- and regioselective 1, 4-difunctionalization of carbon-sulfur double bonds. This represents the first instance of radical-mediated dual-functionalization of X-Y type unsaturated bonds, enabling the synthesis of complex linear molecules with CO, CN, and C-S bonds in a single operation. The method surpasses traditional approaches by avoiding the need for thiourea intermediates and the harsh conditions typically associated with them. The developed strategy exemplifies versatility, being applicable to 1, 4-oxyamination, 1, 4-diamination, and 1, 4-sulfonamination reactions, and has demonstrated compatibility with over 60 different substrates. The research also elucidates the role of electronic complementarity between radicals and receptors in achieving high selectivity in 1, 4-difunctionalization reactions. This study significantly advances the field of bifunctionalization and remote difunctionalization reactions, with profound implications for the development of pharmaceuticals and materials science.
A renewable fluorescent material (G⊂CP5L) has been constructed via supramolecular assembly between a new derivative of pillararene, namely leggero pillar[5]arene, as the host molecule (CP5L) and a tetraphenylethylene (TPE)-based ditopic guest (G). This new material can simultaneously perform efficient detection and separation of silver(Ⅰ) from aqueous environments. Possessing an electron-rich cavity and two cytosine groups modified on both rims, CP5L functions as the host-guest binding site for G and offers exclusive coordination sites for further interaction with Ag+. Adding Ag+ to the system undergoes dramatic fluorescence enhancement due to the mechanism of supramolecular assembly-induced enhanced emission (SAIEE). This fluorescence enhancement allows for efficient and visualized detection following a "light-up" pattern, achieving a limit of detection (LOD) of 1.3 × 10–7 mol/L, which is fully in line with the World Health Organization's drinking water standard of 9 × 10–7 mol/L. In addition, G⊂CP5L also shows strong anti-interference capability against other cationic species. For the separation of Ag+ from aqueous systems, G⊂CP5L displays exceptional adsorption efficiency (97%) and reliable recovery performance, demonstrating excellent recyclability after five experimental cycles without compromising its adsorption activity
Three monomers, namely A2, B2, and GH, were designed and synthesized. By utilizing double host-guest interactions, the monomers A2+B2+GH underwent self-assembly to form a supramolecular linear polymer (SLP) at high concentrations. Long fibers could be pulled from the concentrated SLP solution. Upon the addition of PdCl2(PhCN)2 into the SLP solution, a structural transformation occurred from SLP to a supramolecular crosslinked polymer (SCP) through metal coordination interaction. This transformation induced fluorescence quenching, test paper strips for ion detection experiment confirmed that the SLP had good detection ability for Pd2+. Furthermore, the SCP underwent a transformation into a gel when the concentration exceeded 145 mmol/L. The SCP gel demonstrated sensitivity to different stimuli, such as K+ ions and changes in temperature, accompanied by a reversible transition between sol and gel states. Additionally, rheological analyses indicated that the gel possessed favorable self-healing properties.
Electrocatalysis for nitrate (NO3–) removal from wastewater faces the challenge of merging efficient reduction and high selectivity to nitrogen (N2) with economic viability in a durable catalyst. In this study, bimetallic PdCu/TiOx composite catalysts were synthesized with varying Pd and Cu ratios through electrochemical deposition on defective TiOx nanotube arrays. Denitrification experiments demonstrated that the Pd1Cu1/TiOx catalyst exhibited the highest NO3– removal rate (81.2%) and N2 selectivity (67.2%) among all tested catalysts. Leveraging the exceptional light-responsive property of TiOx, the introduction of light energy as an assisting factor in electrocatalysis further augmented the NO3– treatment rate, resulting in a higher NO3– removal rate of 95.1% and N2 selectivity of approximately 90%. Compared to individual electrocatalysis and photocatalysis systems, the overpotential for the catalytic interface active *H formation in the photo-assisted electrocatalysis system was remarkably reduced, thus accelerating electron migration and promoting NO3– reduction kinetics. Economic analysis revealed an energy consumption of 2.74 kWh/mol and a corresponding energy consumption per order (EEO) of 0.79 kWh/m3 for the Pd1Cu1/TiOx catalyst to reduce 25.2 mg/L of NO3–-N in water to N2, showcasing remarkable competitiveness and economic advantages over other water treatment technologies. This study developed the PdCu/TiOx electrocatalysts with high NO3– removal rates and N2 selectivity, particularly when combined with light energy, the efficiency and selectivity were significantly enhanced, offering a competitive and economically viable solution for wastewater treatment.
2-Azabicyclo[2.1.1]hexanes (aza-BCHs) are constrained pyrrolidine analogues with improved physicochemical characteristics in drug design. Here, we report a direct visible light-mediated photocycloaddition of 4-aza-coumarins with mono- or disubstituted bicyclo[1.1.0]butanes for synthesizing aza-BCHs without an external catalyst. The introduction of the ester group on 4-azacoumarin is critical for direct imine excitation and versatile synthetic utility. Preliminary mechanistic studies indicated that the reaction took place primarily at the triplet hypersurface.
A new oxidative N-heterocyclic carbene (NHC)-catalyzed high-order [7 + 3] annulation reaction of γ-indolyl phenols as 1, 7-dinucleophiles and α, β‐alkynals with the aid of Sc(OTf)3 is reported, enabling the highly regioselective access to unprecedented polyarene-fused ten-membered lactams bearing a bridged aryl-aryl-indole scaffold in moderate to good yields. This protocol demonstrates a broad substrate scope, good compatibility with substituents and complete regioselectivity, providing an organocatalytic modular synthetic strategy for creating medium-sized lactams.
A convenient photocatalytic multi-component reaction of alkenes, quinoxalin-2(1H)-ones, and diazo compounds has been developed in the presence of water. A number of ester-containing quinoxalin-2(1H)-ones could be efficiently obtained in moderate to good yields at room temperature. This metal-free visible-light-driven tandem reaction was conducted through proton-coupled electron transfer (PCET) process using water as the hydrogen donor and 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) as the photocatalyst.
Selective catalytic transfer hydrogenation (CTH) of carbonyl compounds to obtain specific alcohols holds significant importance across various fields. Achieving multiple selectivity in CTH is particularly crucial, but full of great challenge. Herein, a cationic In-captured Zr-porphyrin framework (1) with nanosized pores/cages was successfully constructed and showed high structure stability. Catalytic investigations revealed that 1 displayed highly multi-selective CTH of aldehydes and ketones containing both chemo- and size selectivity for the first time. The CTH of aldehydes and ketones exhibited remarkable reductive selectivity of 99% towards CO bonds into CHOH in the presence of -NO2, -CN and CC groups. Through tuning the reaction conditions, 1 also exhibited highly selective reduction of 97% for -CHO groups in the simultaneous presence of -CHO and -COCH3 groups in intra- and intermolecular settings. Remarkably, reductive selectivity towards -CHO group remained prominent among five concurrent unsaturated groups mentioned above. Additionally, the definite pore size of 1 facilitated volume control of substrates, enabling size selectivity. 1 as a heterogeneous catalyst was further confirmed by leaching tests, and maintained high activity even after being used for at least six cycles. Mechanistic studies have revealed that Zr6O8 clusters served as the catalytic centers and the observed chemoselectivity mainly results from the synergistic effect of distinct metal sites within 1. The heightened selectivity towards -CHO over -COCH3 can be attributed to the easier realization of transfer hydrogenation processes for -CHO compared to -COCH3.
Boron-doped diamond (BDD) is a well-known anode material with a high pollutant degradation ability for electrochemical oxidation wastewater treatment. Nevertheless, the cost of production and mechanical strength of BDD membranes remain unsatisfactory. Magnetic BDD particles derived from industrial waste may represent a promising alternative to BDD membranes, although the challenge remains in assembling these particles into a usable electrode. In this study, magnetic BDD particles were attracted to a Ti/RuO2-IrO2 electrode using a magnet, thus constituting a novel 2.5-dimensional (2.5D) electrode. To ascertain the structure-activity relationship of the novel electrode, essential characterizations, multi-physics simulations, pollutant degradation and electrosynthesis experiments were conducted. The results indicate that an appropriate quantity of BDD particles (0.1 g/cm2) can enhance the number of active sites by approximately 20%. A strong synergistic effect was observed between the Ti/RuO2-IrO2 and BDD particles in the degradation of various pollutants, including azo dye, p-benzoquinone, succinic acid and four kinds of real wastewaters, as well as glycerol conversion. The joint active sites on the interface between Ti/RuO2-IrO2 and BDD particles, as well as the inner active sites on BDD particles, have been identified as crucial in the mineralization of pollutants and the generation of value-added products. The optimal amount of BDD particles (0.1 g/cm2) is sufficient to preserve the joint active sites and to maintain an adequate polarization on the BDD particles. Nevertheless, the hybrid feature of the 2.5D electrode is diminished when a greater quantity of BDD particles (0.3 g/cm2) is loaded.
Lithium metal has emerged as a highly promising anode material for enhancing the energy density of secondary batteries, attributed to its high theoretical specific capacity and low electrochemical potential. However, safety concerns related to lithium dendrite-induced short circuits and suboptimal electrochemical performance have impeded the commercial viability of lithium metal batteries. Current research efforts primarily focus on altering the solvated structure of Li+ by modifying the current collector or introducing electrolyte additives to lower the nucleation barrier, expedite the desolvation process, and suppress the growth of lithium dendrites. Nevertheless, an integrated approach that combines the advantages of these two strategies remains elusive. In this study, we successfully employed metal-organic salt additives with lithophilic properties to accelerate the desolvation process, reduce the nucleation barrier of Li+, and modulate its solvated structure. This approach enhanced the inorganic compound content in the solid electrolyte interphase (SEI) on lithium foil surfaces, leading to stable Li+ deposition and stripping. Specifically, LiCu cells demonstrated excellent cycle life and Coulombic efficiency (97.28% and 98.59%, respectively) at 0.5 mA/cm2@0.5 mAh/cm2 and 1 mA/cm2@1 mAh/cm2 for 410 and 240 cycles, respectively. LiLi symmetrical cells showed no short circuit at 1 mA/cm2@1 mAh/cm2 for 1150 h, and LiLFP full cells retained 68.9% of their capacity (104.6 mAh/g) after 250 cycles at N/P (1.1:1.0) with a current density of 1 C.
Although supramolecular transformations have been emerged as a potent strategy for transitioning between various topologies, post-modification induced topological transformations have never been explored in the context of [2]catenane topologies. In this study, we present a novel supramolecular transformation between a Hopf link and a macrocycle, induced by the Diels–Alder click reaction. By strategically selecting the half-sandwich ruthenium binuclear fragment B as a rigid capping agent, we successfully integrated tetrazine moieties into the metalla[2]catenane structure. We demonstrated that the introduction of 2,5-norbornadiene (NBD) as an external stimulus allows for the transformation of the novel metalla[2]catenane, featuring reactive tetrazine sites, into the corresponding monomeric ring through post-modification for the first time. The synthetic results are corroborated by single-crystal X-ray diffraction analysis, ESI-TOF/MS, elemental analysis, and detailed solution-state NMR techniques.
Aryl-ether bonds are facile to attack by oxidizing radicals, thus stimulating the exploitation of ether-free polymers as proton exchange membranes (PEMs) for the long-lasting operation of fuel cells. In this study, a novel class of PEMs derived from all-carbon fluorinated backbone polymers containing sulfide-linked alkyl sulfonic acid side chains have been developed through a straightforward and effective synthetic procedure. The sulfide-linked alkyl sulfonate groups were tethered to the poly(triphenylene pentafluorophenyl) backbone through a quantified and site-specific para-fluoro-thiol click reaction. Owing to the existence of obvious phase separation morphology between hydrophobic main chain and hydrophilic sulfonate groups in the side chains, resulting PEMs demonstrated favorable proton conductivity of 142.5 mS/cm at 80 ℃, while maintaining excellent dimensional stability with an in-plane swelling ratio of <17% as well as a through-plane swelling ratio of <25%. They also exhibit elevated thermal decomposition temperatures (Td5% exceeding 300 ℃) alongside high tensile strength (>50 MPa). Furthermore, the ether-free full-carbon fluorinated main chain and the -S- group in the side chain, which serves as an effective free-radical scavenger, providing good chemical stability during Fenton's test. The PEMs achieved a maximum power density of 407 mW/cm2 in a single H2/air fuel cell, and an open-circuit voltage decline rate of 0.275 mV/h in a durability test at 30% RH and 80 ℃. Concurrently, the hydrogen crossover current density is only 1/3 of that of Nafion 212. These findings reveal that the resulted PEMs display considerable antioxidative properties along with commendable performance, with prospective applications in proton exchange membrane fuel cells.
Single-molecule junctions are building blocks for constructing molecular devices. However, intermolecular interactions like winding bring additional interference among the surrounding molecules, which inhibits the intrinsic coherent transport through single-molecule junctions. Here, we employed a nanocavity (dimethoxypillar[5]arene, DMP[5]), which is analogous to electric cables, to confine the conformation of flexible chains (1,8-diaminooctane, DAO) via host-guest interaction. Single-molecule conductance measurements indicate that the conductance of DAO encapsulated with DMP[5] is as high as that of pure DAO, as reproduced by theoretical simulations. Intriguingly, the molecular lengths of the DAO encapsulated with DMP[5] increase from 1.13 nm to 1.46 nm compared with the pure DAO, indicating that DMP[5] keeps DAO upright-standing via the confinement effect. This work provides a new strategy to decouple the intermolecular interaction by employing an insulating sheath, enabling the high-density integration of single-molecule devices.
A pair of asymmetric rigid carbazole-benzonitrile-based emitters were synthesized by strategically alternating donor and acceptor groups along the molecular edges. The spin-flip process is accelerated by both the formation of localized and delocalized charge transfer states due to linearly positioned donors and strong spin-orbital coupling between different excitation feature of the lowest singlet and triplet excited states. This molecular architecture results in a remarkable short delayed lifespan of around 100 ns. The application of the two emitters in organic light-emitting diodes (OLEDs) achieves the highest external quantum efficiencies of 13.0% for the green emitter and 9.1% for the sky-blue emitter. Impressively, these devices maintain their high efficiency even at high luminance levels. The sustained efficiency is ascribed to the effective suppression of exciton quenching by substantially shortening delayed lifespan. These findings underscore the practical utility of the molecular design strategy that incorporates alternate donor and acceptor groups at the molecular periphery for shortening delayed fluorescence lifetime, and hold great promise for the development of high-performance OLEDs.
Electromagnetic wave-absorbing materials (EWAMs) are susceptible to failure in complex chemical environments. It is urgent to develop composites with high-efficiency electromagnetic wave (EMW) absorption and strong corrosion resistance. In the work, polyaniline (PANI) is in-situ polymerized on the surface of oxidized carbon nanohorns (ox-CNHs) to create a core-shell composite of ox-CNHs@PANI. By adjusting the thickness of the PANI shell and effectively regulating the electromagnetic parameters of the composite material, excellent impedance matching and efficient EMW absorption are achieved. At a thickness of 2.22 mm, the composite exhibits a reflection loss peak (RLmin) and a maximum effective absorption broadband (EAB) of −66.7 dB and 5.68 GHz, respectively. Additionally, the dense PANI shell effectively prevents contact between the corrosive medium and ox-CNHs, which significantly reduces the possibility of corrosion. Due to the formation of the ox-CNHs/PANI interface, the ox-CNHs@PANI composite exhibits strong corrosion resistance under acidic, alkaline, and neutral conditions. The ox-CNHs@PANI composite exhibits excellent EMW absorption and strong corrosion resistance, offering a new approach to developing advanced bifunctional materials.
Molecular catalysts can effectively steer the electrocatalytic acetylene semihydrogenation into ethylene, but realizing high Faradaic efficiency (FE) at industrial current densities remains a challenge. Herein, we report a ligand engineering strategy that utilizes polymeric N-heterocyclic carbene (NHC) as a hydrophobic ligand to modulate the microenvironment of Cu sites. This polymeric NHC imparts appropriate hydrophobic properties for the chelated Cu sites, thereby moderating the H2O transport and enabling easy access of acetylene. Consequently, the polymeric NHC chelated Cu exhibits an FEethylene of ~97% at a current density of 500 mA/cm2 in a flow cell. Particularly in a zero-gap reactor, the FEethylene consistently exceeds 86% across current densities from 100 mA/cm2 to 400 mA/cm2, reaching an optimal FEethylene of 98% at 200 mA/cm2 and achieving durable operation for 155 h at 100 mA/cm2. This work provides a promising paradigm to regulate the microenvironment of molecular catalysts for improving electrocatalytic performances under industrial current densities.
Recently, CsPbBr3 perovskite solar cells (PSCs) have garnered attention due to cost-effectiveness and reliability. However, hole transport limitations lead to charge recombination and lower power conversion efficiency (PCE). Defects in the CsPbBr3 layer, poor hole transport at the interface with carbon electrodes, and energy level differences hinder performance. Optimizing the perovskite layer using electron-donating organic molecules containing -NH2 groups enhances efficiency and stability by passivating defects and modulating lattice structure. In this work, tetra(4-aminophenyl)ethylene (TPE) and tetra(4-aminobiphenyl)ethylene (TPE-Ph) were employed to optimize the CsPbBr3/carbon electrode interface. Their strong electron-donating properties and amino groups facilitate hole transfer and defect passivation, boosting PCE to 9.38% and enhancing stability.
Epoxy resin is widely used in electronic packaging due to its exceptional performance, particularly the low-temperature curable thiol/epoxy system, which effectively minimizes thermal damage to sensitive electronic components. However, the majority of commercial thiol curing agents contain hydrolysable ester bonds and lack rigid structures, which induces most of thiol/epoxy systems still suffering from unsatisfactory heat resistance and hygrothermal resistance, significantly hindering their application in electronic packaging. In this study, we synthesized a tetrafunctional thiol compound, bis[3-(3-sulfanylpropyl)-4-(3-sulfanylpropoxy)phenyl]sulfone (TMBPS) with rigid and ester-free structures to replace traditional commercial thiol curing agents, pentaerythritol tetra(3-mercaptopropionate) (PETMP). Compared to the PETMP/epoxy system, the TMBPS/epoxy system exhibited superior comprehensive properties. The rigid structures of bisphenol S-type tetrathiol enhanced the heat resistance and mechanical properties of TMBPS/epoxy resin cured products, outperforming those of PETMP/epoxy resin cured products. Notably, the glass transition temperature of TMBPS/epoxy resin cured products was 74.2 ℃ which was 11.8 ℃ higher than that of PETMP cured products. Moreover, the ester-free structure in TMBPS contributed to its enhanced resistance to chemicals and hygrothermal conditions. After undergoing 1000 h of high-temperature and high-humidity aging, the tensile strength and adhesion strength of TMBPS-cured products were 73.33 MPa and 3.39 MPa, respectively exceeding 100% and 40% of their initial values, while PETMP-cured products exhibited a complete loss of both tensile strength and adhesion strength. This study provides a strategy for obtaining thermosetting polymers that can be cured at low temperatures and exhibit excellent comprehensive properties.
Rapid carrier recombination and slow charge transfer dynamics have significantly reduced the performance of photocatalytic hydrogen production. Construction of heterojunctions via utilizing the sulfur-edge and metal-edge sites of metal sulfide semiconductor for improving photocatalytic activity remains a significant challenge. Herein, a novel ZnIn2S4/MnS S-scheme heterojunction was prepared by hydrothermal synthesis to accelerate charge carrier transfer for efficient photocatalysis. Notably, ZnIn2S4/MnS exhibited excellent photocatalytic hydrogen evolution activity (7.95 mmol g−1 h−1) under visible light irradiation (≥420 nm), up to 4.7 times higher than that of pure ZnIn2S4. Additionally, cycling experiments showed that ZM-2 remained high stability after four cycles. Density-functional theory (DFT) calculations and in situ XPS results confirm the formation of S-scheme heterojunction, indicating that the tight interfacial contact between ZnIn2S4 and MnS with the presence of Mn-S bonds (the unsaturated Mn edges of MnS and the uncoordinated S atoms in the edge of ZnIn2S4) promoted faster charge transfer. Besides, the unsaturated S atom on the surface of MnS is an active site with strong H+ binding ability, which can effectively reduce the overpotential or activation barrier for hydrogen evolution. This study illustrates the critical influence of the interfacial Mn-S bond on the ZnIn2S4/MnS S-scheme heterojunction to achieve efficient photocatalytic hydrogen production and provides relevant guidance for carrying out rational structural/interfacial modulation.
Carbon emissions from wastewater treatment contribute to global warming and have received widespread attention. It is necessary to seek low-carbon wastewater treatment technologies. Microbial fuel cells (MFC) and osmotic microbial fuel cells (OsMFC) are low-carbon technologies that enable both wastewater treatment and energy recovery. In this study, MFC and OsMFC were used to treat sulfamethoxazole (SMX) wastewater, and direct carbon emissions during operation was calculated. The highest SMX removal rate can reach about 40%. Simultaneously, the CH4 emission factor was significantly reduced to <6 g CO2/kg of chemical oxygen demand. The accumulation of SMX-degrading bacteria competed with methanogens for carbon source utilization, leading to a significant decrease in the relative abundance of methanogens. It is hoped that this study can provide a sustainable approach to antibiotic wastewater treatment and promote the development of low-carbon wastewater treatment technologies.
Broadband photothermal and photoacoustic agents in the near-infrared (NIR) biowindow are of significance for cancer phototheranostics. In this work, PtCu nanosheets with an average lateral size of less than 10 nm are synthesized as NIR photothermal and photoacoustic agents in vivo, which show strong light absorption from NIR-Ⅰ to NIR-Ⅱ biowindows with the photothermal conversion efficiencies of 20.4% under 808 nm laser and 32.7% under 1064 nm laser. PtCu nanosheets functionalized with folic acid-modified thiol-poly(ethylene glycol) (SH-PEG-FA) present good biocompatibility and 4T1 tumor-targeted effect, which give high-contrast photoacoustic imaging and efficient photothermal ablation of 4T1 tumor in both NIR-Ⅰ and NIR-Ⅱ biowindows. Our work significantly broadens applications of noble metal-based nanomaterials in the fields of cancer phototheranostics by rationally designing their structures and modulating their physicochemical properties.
Protein damage repair and prevention are important objectives in skin care industry. Skin protein damage or modifications such as glycation, carbonylation or oxidation, have a significant impact on its function, therefore directly influencing various skin functions or properties including skin appearance. However, there is a lack of comprehensive methods to visualize and assess the protein damage. In this article, we present a three-channel imaging approach to simultaneously visualize and quantitatively evaluate protein oxidation, protein glycation and carbonylation in a full-thickness skin model. We successfully visualized and quantified the impact of the multiple stimuli (ultraviolet radiation A (UVA) and/or methylglyoxal) as well as treatment effect of positive control (vitamins C and E) with this method. Our findings indicate that multiple stimuli exhibit synergistic effects on protein damage. Furthermore, we evaluated a unique combination of skin care ingredients which demonstrated an excellent efficacy in resisting protein damage. Further research revealed that three ingredients of the combination upregulate autophagy in cells, which may contribute to remove damaged proteins and maintain protein quality homeostasis. This method provides a holistic assessment of protein damages and can be employed to evaluate the impact of various stimuli or to assess the efficacy of skin care ingredients in mitigating such damage.
Sodium metal has been widely studied in the field of batteries due to its high theoretical specific capacity (~1,166 mAh/g), low redox potential (-2.71 V compared to standard hydrogen electrode), and low-cost advantages. However, problems such as unstable solid electrolyte interface (SEI), uncontrolled dendrite growth, and side reactions between solid-liquid interfaces have hindered the practical application of sodium metal anodes (SMAs). Currently, lots of strategies have been developed to achieve stabilized sodium metal anodes. Among these strategies, modified metal current collectors (MCCs) stand out due to their unique role in accommodating volumetric fluctuations with superior structure, lowering the energy barrier for sodium nucleation, and providing guided uniform sodium deposition. In this review, we first introduced three common metal-based current collectors applied to SMAs. Then, we summarized strategies to improve sodium deposition behavior by optimally engineering the surface of MCCs, including surface loading, surface structural design, and surface engineering for functional modification. We have followed the latest research progress and summarized surface optimization cases on different MCCs and their applications in battery systems.
For large-scale energy storage devices, all-solid-state sodium-ion batteries (SIBs) have been revered for the abundant resources, low cost, safety performance and a wide operating temperature range. Na-ion solid-state electrolytes (Na-ion SSEs) are the critical parts and mostly determine the electrochemical performance of SIBs. Among the studied ones, inorganic Na-ion SSEs stand out for their good safety performance and high ionic conductivity. In this review, we outline the research progress of inorganic SSEs in SIBs based on the perspectives of crystal structure, performance optimization, synthesis methods, all-solid-state SIBs, interface modification and related characterization techniques. We hope to provide some ideas for the design of future high-performance Na-ion SSEs.
With the development of science and technology, there is an increasing demand for energy storage batteries. Aqueous zinc-ion batteries (AZIBs) are expected to become the next generation of commercialized energy storage devices due to their advantages. The aqueous zinc ion battery is generally composed of zinc metal as the anode, active material as the cathode, and aqueous electrolyte. However, there are still many problems with the cathode/anode material and voltage window of the battery, which limit its use. This review introduces the recent research progress of zinc-ion batteries, including the advantages and disadvantages, energy storage mechanisms, and common cathode/anode materials, electrolytes, etc. It also gives a summary of the current research status of each material and provides solutions to the problems they face. Finally, it looks at the future direction and methods to optimize the performance of zinc-ion full batteries.
Multi-metal porous crystalline materials (MPCM), integrating the functions of both multi-metal centres and porous crystalline materials (e.g., metal-organic frameworks (MOFs) and covalent organic frameworks (COFs)), are an extended class of porous materials that have attracted much attention for a broad range of applications. Owing to the advantages of these materials, they generally display high porosity, multi-metal active sites, well-tuned functions, and pre-designable structures, etc., serving as desired platforms for the study of structure-property relationships. In view of the clean and sustainable target, a series of MPCM have been explored as electrocatalysts for electrocatalytic reactions like hydrogen evolution reaction, oxygen evolution reaction and electrocatalytic CO2 reduction reaction. Concerning the progress achieved for MPCM in electrocatalytic field during past years, this review will provide a brief introduction on the recent breakthrough of MPCM based electrocatalysts including their synthesis methods, structure design, component/morphology tuning, electrocatalytic property and structure-property relationship, etc. Besides, it will also conclude the current challenges and present perspectives for the MPCM based electrocatalysts, which might promote the development of porous crystalline materials in electrocatalysis and hope to provide new insights for scientists in related fields.
Protein glycosylation and phosphorylation, as two of the most important protein post-translational modifications (PTMs), play key roles in living organisms. However, glycopeptides and phosphopeptides have low abundance in biological samples. In addition, the low ionization efficiency and the severe signal interference in the presence of other peptides present great difficulties for their direct mass spectrometry (MS) analysis. Therefore, it is important to develop feasible enrichment strategies to pretreat glycopeptides and phosphopeptides in complex samples before MS detection. This paper reviews the application of various magnetic nanomaterials (MNMs) in glycopeptides and phosphopeptides in the last decade, with emphasis on the enrichment principles, the design and synthesis process of the materials, and the effectiveness of the application in biological samples. In addition, possible future trends and potential challenges are presented.
Sulfide solid electrolytes with an ultrahigh ionic conductivity are considered to be extremely promising alternatives to liquid electrolytes for next-generation lithium batteries. However, it is difficult to obtain a thin solid electrolyte layer with good mechanical properties due to the weak binding ability between their powder particles, which seriously limits the actual energy density of sulfide all-solid-state lithium batteries (ASSLBs). Fortunately, the preparation of sulfide-polymer composite solid electrolyte (SPCSE) membranes by introducing polymer effectively reduces the thickness of solid electrolytes and guarantees high mechanical properties. In this review, recent progress of SPCSE membranes for ASSLBs is summarized. The classification of components in SPCSE membranes is first introduced briefly. Then, the preparation methods of SPCSE membranes are categorized according to process characteristics, in which the challenges of different methods and their corresponding solutions are carefully reviewed. The energy densities of the full battery composed of SPCSE membranes are further given whenever available to help understanding the device-level performance. Finally, we discuss the potential challenges and research opportunities for SPCSE membranes to guide the future development of high-performance sulfide ASSLBs.
Mesoporous silica nanoparticles (MSNs) are thought to be an attractive drug delivery material because of their advantages including high specific surface area, tunable pore size and morphology, easy surface modification and good biocompatibility. However, as a result of the poor biodegradability of MSNs, their biomedical applications are limited. To break the bottleneck of limited biomedical applications of MSNs, more and more researchers tend to design biodegradable MSNs (b-MSNs) nanosystems to obtain biodegradable as well as safe and reliable drug delivery carriers. In this review, we focused on summarizing strategies to improve the degradability of MSNs and innovatively proposed a series of advantages of b-MSNs, including controlled cargo release behavior, multifunctional frameworks, nano-catalysis, bio-imaging capabilities and enhanced therapeutic effects. Based on these advantages, we have innovatively summarized the applications of b-MSNs for enhanced tumor theranostics, including enhanced chemotherapy, delivery of nanosensitizers, gas molecules and biomacromolecules, initiation of immune response, synergistic therapies and image-guided tumor diagnostics. Finally, the challenges and further clinical translation potential of nanosystems based on b-MSNs are fully discussed and prospected. We believe that such b-MSNs delivery carriers will provide a timely reference for further applications in tumor theranostics.
Natural phytoconstituents exhibit distinct advantages in the management and prevention of inflammatory bowel disease (IBD), attributed to their robust biological activity, multi-target effects, and elevated safety profile. Although promising, the clinical application of phytoconstituents have been impeded by poor water solubility, low oral bioavailability, and inadequate colonic targeting. Recent advancements in nanotechnology has offered prospective avenues for the application of phytoconstituents in the treatment of IBD. A common strategy involves encapsulating or conjugating phytoconstituents with nanocarriers to enhance their stability, prolong intestinal retention, and facilitate targeted delivery to colonic inflammatory tissues. Furthermore, drawing inspiration from the self-assembling nanostructures that emerge during the decoction process of Chinese herbs, a variety of natural active compounds-based nanoassemblies have been developed for the treatment of IBD. They exhibit high drug-loading capacities and surmount the challenges posed by poor water solubility and low bioavailability. Notably, phyto-derived nanovesicles, owing to their unique structure and biological functions, can serve as therapeutic agents or novel delivery vehicles for the treatment of IBD. Consequently, this review provides an extensive overview of emerging phytoconstituent-derived nano-medicines/vesicles for the treatment of IBD, intending to offer novel insights for the clinical management of IBD.
As one of the most common gynecological malignancies, peritoneal metastasis is a common feature and cause of high mortality in ovarian cancer (OC). Currently, the standard treatment for OC and its peritoneal metastasis is maximal cytoreductive surgery (CRS) combined with platinum-based chemotherapy. Compared with intravenous chemotherapy, traditional intraperitoneal (IP) chemotherapy exhibits obvious pharmacokinetic (PK) advantages and systemic safety and has shown significant survival benefits in several clinical studies of OC patients. However, there remain several challenges in traditional IP chemotherapy, such as insufficient drug retention, a lack of tumor targeting, inadequate drug penetration, gastrointestinal toxicity, and limited inhibition of tumor metastasis and chemoresistance. Nanomedicine-based IP targeting delivery systems, through specific drug carrier design with tumor cells and tumor environment (TME) targeting, make it possible to overcome these challenges and maximize local therapy efficacy while reducing side effects. In this review article, the rationale and challenges of nanomedicine-based IP chemotherapies, as well as their in vivo fate after IP administration, which are crucial for their rational design and clinical translation, are firstly discussed. Then, current strategies for nanomedicine-based targeting delivery systems and the relevant clinical trials in IP chemotherapy are summarized. Finally, the future directions of the nanomedicine-based IP targeting delivery system for OC and its peritoneal metastasis are proposed, expecting to improve the clinical development of IP chemotherapy.
Covalent organic frameworks (COFs) are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability, good crystallinity, a large specific surface area, and controllable structures. COFs are widely used in the fields of adsorption and separation, catalysis, photovoltaics, and drug-delivery. The structural regulation and performance optimization of COFs can be realized through the modification of ligands and the selection of linkage methods. In which, the types of linkage are closely related to the stability and performance of COFs. In this review, nitrogen-containing linkage-bonds (NCLBs) in COFs are divided into N-containing double bonds, N-containing conjugated rings and N-containing unconjugated rings. The association between structure and performance of COFs is elaborated and the synthesis methods of COFs are systematically summarized. Moreover, the structural design, theoretical prediction and machinable application of COFs are prospected
Pollutants contained in wastewater pose serious harm to the environment. Graphene-based water treatment materials show significant advantages in wastewater treatment. However, with the development of graphene-based materials, its progress in water treatment has reached a bottleneck. The challenge lies in effectively enhancing its performance in water treatment and ensuring its practicality. By employing biomimetic approaches, some exceptional properties and structures found in nature can be mimicked in graphene materials, effectively enhancing graphene’s adsorption and mechanical properties. Current biomimetic methods include biomimetic mineralization, self-assembly, and templating. unfortunately, all of the above methods suffer from the disadvantages of complexity and poor bionic effect. Nevertheless, 3D printing, a form of additive manufacturing (AM) technology, offers integrated molding and excellent biomimetic performance in creating biomimetic materials. This paper will cover the following aspects: (1) An overview of objects suitable for bionics in terms of functional and structural aspects, along with their properties, and a discussion of various bionic objects combined with graphene materials in water treatment and related research; (2) a comparison of different methods for preparing graphene-based bionic materials; (3) an examination of the current drawbacks and limitations of graphene-based biomimetic materials; and (4) a conclusion and future prospects, exploring the potential of using 3D printing technology to produce graphene biomimetic materials. This review aims to serve as a guide for effectively leveraging natural inspirations to create graphene-based biomimetic materials and enhance graphene properties.
Graphene quantum dots (GQDs) are a class of promising carbon-based nanomaterials that have attracted considerable interest from researchers due to their excellent physical, chemical, and biological properties. However, the high cost, toxicity, and laborious preparation process of GQDs also limit their widespread use. To address this issue, the actual research directions consist in replacing traditional non-renewable feedstocks via screening cheap, easily available, and renewable biomass materials based on the concept of resource conservation and environmental friendliness. Herein, the state-of-the-art technologies in the green preparation of GQDs using biomass as carbon source are reported. Initially, the green synthesis strategies as well as the structural, optical, and biosafety properties of GQDs are discussed in detail. Subsequently, the most representative applications of GQDs in energy and environmental remediation fields are summarized. Finally, the current challenges and future potential of the GQDs are presented.
Advanced oxidation processes (AOPs) governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation. Nevertheless, the low diffusion rates, inadequate interactions of the reactants, and limited active site exposure hinder treatment efficiency. Porous carbocatalysts with high specific surface area, tunable pore size, and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants. The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions. Additionally, the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites, which further enhances the catalytic activity. This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts. Moreover, engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances. Challenges and future research opportunities pertaining to the design, optimization, mechanistic investigation, and practical application of porous carbocatalysts in peroxide activation are also proposed.
Electrochemical water splitting presents a promising, environmentally friendly alternative to fossil fuels for hydrogen production. However, the efficiency is constrained by the sluggish kinetics and high overpotentials associated with the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). While noble metal catalysts, such as Pt for HER and Ir for OER, currently offer superior performance, their widespread adoption is hindered by high cost and scarcity. This has spurred research into cost-effective alternatives, with a focus on understanding the underlying electrocatalytic mechanisms. MXenes, a class of two-dimensional materials, have emerged as promising candidates for electrocatalytic water splitting due to their unique physical and chemical properties. However, research in this field remains largely experimental, lacking a comprehensive understanding of fundamental mechanisms. This knowledge gap impedes the development of high-efficiency electrocatalysts and necessitates further investigation. This review systematically examines recent advancements in MXene-based nanohybrids for electrocatalytic water splitting, covering synthetic methods, structure-property relationships, and performance enhancement strategies. It encompasses both precious and non-noble metal-based systems for HER, OER, and overall water splitting applications. Additionally, this review addresses current challenges, opportunities, and future research directions for MXene-based nanohybrids. By providing comprehensive insights into the development of high-performance MXene-based electrocatalysts, this review aims to accelerate progress in the field of electrochemical water splitting. It serves as a valuable resource for researchers and engineers working towards more efficient and sustainable hydrogen production technologies, potentially contributing to the broader goal of transitioning away from fossil fuels towards cleaner energy sources.
The transition metal-catalyzed C-H activation have been considered as increasingly useful approach for installing new functional groups onto organic small molecules due to their high step- and atom-economy, the abundance of hydrocarbon compounds, and the potential for late-stage functionalization of complex organic molecules. The ortho- and meta-C-H activation and functionalization of aromatic compounds have been widely explored in recent years, however the distal para-C-H activation and functionalization has remained a significant challenge because of the difficulty in forming energetically favorable metallacyclic transition states. The utilization of appropriate directing groups or templates as well as the meticulous design of catalysts and ligands has proven to be effective in transition-metal-catalyzed remote para-C-H bonds activation and functionalization of aromatic compounds. This review aims to summarize the strategies for controlling para-selective C-H functionalization using the directing group, template engineering, and catalyst/ligand design under transition metals catalysis in recent years.
Supramolecular luminescent materials (SLMs) exhibit exceptional luminescence properties and the ability to be intelligently regulated through diverse assembly approaches, making them highly attractive in the field of luminescent materials. In recent years, the novel macrocyclic arenes characterized by unique electron-rich structures, ease of derivatization, tunable conformations and even inherent luminescence properties afford much opportunities to create such dynamic smart luminescent materials. The incorporation of macrocyclic arenes into SLMs leads to simple preparation process, diverse photophysical phenomena and sophisticated regulatory mechanisms, which is also currently one of the most frontier and hot topics in macrocyclic and supramolecular chemistry and even luminescent materials. In this review, the research advances in construction and applications of SLMs based on macrocyclic arenes in the last several years will be presented from the different assembly strategies, including host-guest complexes, supramolecular polymers, nanoparticles, and other assemblies. Moreover, some insights into future directions for this research area will also be offered.
Quantum dots (QDs), a type of nanoscale semiconductor material with unique optical and electrical properties like adjustable emission and high photoluminescence quantum yields, are suitable for applications in optoelectronics. However, QDs are typically degraded under humid and high-temperature circumstances, greatly limiting their practical value. Coating the QD surface with an inorganic silica layer is a feasible method for improving stability and endurance in a variety of applications. This paper comprehensively reviews silica coating methodologies on QD surfaces and explores their applications in optoelectronic domains. Firstly, the paper provides mainstream silica coating approaches, which can be divided into two categories: in-situ hydrolysis of silylating reagents on QD surfaces and template techniques for encapsulation QDs. Subsequently, the recent applications of the silica-coated QDs on optoelectronic fields including light-emitting diodes, solar cells, photodetectors were discussed. Finally, it reviews recent advances in silica-coated QD technology and prospects for future applications.
Enhancing the corrosion resistance of carriers within Fenton-like systems and inhibiting the migration and aggregation of single atoms in reaction environments are essential for maintaining both high activity and stability at catalytic sites, thus meeting fundamental requirements for practical application. The Fenton-like process of activating various strong oxidants by silicon-based single atom catalysts (SACs) prepared based on silicon-based materials (mesoporous silica, silicon-based minerals, and organosilicon materials) has unique advantages such as structural stability (especially important under strong oxidation conditions) and environmental protection. In this paper, the preparation strategies for the silicon-based SACs were assessed first, and the structural characteristics of various silicon-based SACs are systematically discussed, their application process and mechanism in Fenton-like process to achieve water purification are investigated, and the progress of Fenton-like process in density functional theory (DFT) of silicon-based derived single atom catalysts is summarized. In this paper, the preparation strategies and applications of silicon-based derived SACs are analyzed in depth, and their oxidation activities and pathways to different pollutants in water are reviewed. In addition, this paper also summarizes the device design and application of silicon-based derived SACs, and prospects the future development of silicon-based SACs in Fenton-like applications.
Organic semiconductor materials have demonstrated extensive potential in the field of gas sensors due to the advantages including designable chemical structure, tunable physical and chemical properties. Through density functional theory (DFT) calculations, researchers can investigate gas sensing mechanisms, optimize, and predict the electronic structures and response characteristics of these materials, and thereby identify candidate materials with promising gas sensing applications for targeted design. This review concentrates on three primary applications of DFT technology in the realm of organic semiconductor-based gas sensors: (1) Investigating the sensing mechanisms by analyzing the interactions between gas molecules and sensing materials through DFT, (2) simulating the dynamic responses of gas molecules, which involves the behavior on the sensing interface using DFT combined with other computational methods to explore adsorption and diffusion processes, and (3) exploring and designing sensitive materials by employing DFT for screening and predicting chemical structures, thereby developing new sensing materials with exceptional performance. Furthermore, this review examines current research outcomes and anticipates the extensive application prospects of DFT technology in the domain of organic semiconductor-based gas sensors. These efforts are expected to provide valuable insights for further in-depth exploration of DFT applications in sensor technology, thereby fostering significant advancements and innovations in the field.
Bacterial pneumonia is one of the most common infectious diseases, a great threat to the health of children and the elderly. In the clinic, due to the extensive use of antibiotics, multi-drug-resistant bacteria have increased in large numbers, seriously affects the treatment of patients with bacterial pneumonia. With the development of nanomedicine, it shows great potential in the treatment of bacterial pneumonia. In this review, it initially comprehensively describes the pathological process of bacterial pneumonia and the current status of its clinical treatment. Then it summarizes the strategies of nanomedicine for the treatment of bacterial pneumonia, including inorganic nanomaterials, polymer nanoparticles, natural source nanomaterials and artificial antimicrobial peptides, with a focus on novel nanomaterials for the treatment of bacterial pneumonia (biomimetic nanomaterials, nanovaccines and genetically engineered nanomaterials). Finally, the prospect of nanomedicine for bacterial pneumonia therapy is discussed in the hope of providing new ideas for the clinical treatment of bacterial pneumonia.

Conventional hydrometallurgy recycling process for treating wasted lithium-ion batteries (LIBs) typically results in the consumption of large amounts of corrosive leachates. Recent research on reusable leachate is expected to significantly improve the economic and environmental benefits, but is usually limited to specific and unique chemical reactions which could only apply to one type of metal elements. Herein, we report the co-extraction of multiple metal elements can be extracted without adding precipitates by mixed crystal co-precipitation, which enables the reusability of the leachate. We show that an oxalic acid (OA): choline chloride (ChCl): ethylene glycol (EG) type DES leachate system can leach transition metals from wasted LiNixCoyMn1-x-yO2 (NCM) cathode materials with satisfactory efficiency (The time required for complete leaching at 120 ℃ is 1.5 h). The transition metals were then efficiently extracted (with a recovery efficiency of over 96% for all elements) by directly adding water without precipitants. Noteworthy, the leachate can be efficiently recovered by directly evaporating the added water. The successful realization of reusability of leachate for the synergistic extraction of multiple elements relies on the regulation of the mixed crystal co-precipitation coefficient, which is realized by rationally design the reaction condition (composition of leachate, temperature and time) and induces the extraction of originally soluble manganese element. Our strategy is expected to be generally applicable and highly competent for industrial applications.
Even the sulfur cathode in lithium-sulfur (Li-S) battery has the advantages of high theoretical energy density, wide source of raw materials, no pollution to the environment, and so on. It still suffers the sore points of easy electrode collapse due to large volume expansion during charge and discharge and low active materials utilization caused by the severe shuttle effect of lithium polysulfides (LiPSs). Therefore, in this work, ramie gum (RG) was extracted from ramie fiber degumming liquid and used as the functional binder to address the above problems and improve the Li-S battery's performance for the first time. Surprisingly, the sulfur cathode using RG binder illustrates a high initial capacity of 1152.2 mAh/g, and a reversible capacity of 644.6 mAh/g after 500 cycles at 0.5 C, far better than the sulfur cathode using polyvinylidene fluoride (PVDF) and sodium carboxymethyl cellulose (CMC) binder. More importantly, even if the active materials loading increased to as high as 4.30 mg/cm2, the area capacity is still around 3.1 mAh/cm2 after 200 cycles. Such excellent performances could be attributed to the abundant oxygen- and nitrogen-containing functional groups of RG that can effectively inhibit the shuttle effect of LiPSs, as well as the excellent viscosity and mechanical properties that can maintain electrode integrity during long-term charging/discharging. This work verifies the feasibility of RG as an eco-friendly and high-performance Li-S battery binder and provides a new idea for the utilization of agricultural biomass resources.
Although lithium-ion batteries (LIBs) currently dominate a wide spectrum of energy storage applications, they face challenges such as fast cycle life decay and poor stability that hinder their further application. To address these limitations, element doping has emerged as a prevalent strategy to enhance the discharge capacity and extend the durability of Li-Ni-Co-Mn (LNCM) ternary compounds. This study utilized a machine learning-driven feature screening method to effectively pinpoint four key features crucially impacting the initial discharge capacity (IC) of Li-Ni-Co-Mn (LNCM) ternary cathode materials. These features were also proved highly predictive for the 50th cycle discharge capacity (EC). Additionally, the application of SHAP value analysis yielded an in-depth understanding of the interplay between these features and discharge performance. This insight offers valuable direction for future advancements in the development of LNCM cathode materials, effectively promoting this field toward greater efficiency and sustainability.
In this work, the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitrogen-doped carbon shell are reported. Selenization temperature plays a significant role in determining the phases, morphology, and lithium-ion storage performance of the composite. Notably, the optimal electrode demonstrates an ultrahigh reversible capacity of 1298.2 mAh/g after 100 cycles at 0.2 A/g and an outstanding rate capability with the capacity still maintained 505.7 mAh/g after 300 cycles at 1.0 A/g, surpassing the calculated theoretical capacity according to individual component and most of the reported MoSe@C- or ZnSe@C-based anodes. Furthermore, ex-situ X-ray diffraction patterns reveal the combined conversion and alloying reaction mechanisms of the composite.
Industrial high-current-density oxygen evolution catalyst is the key to accelerating the practical application of hydrogen energy. Herein, Co9S8/CoS heterojunctions were rationally encapsulated in S, N-codoped carbon ((Co9S8/CoS)@SNC) microleaf arrays, which are rooted on S-doped carbonized wood fibers (SCWF). Benefiting from the synergistic electronic interactions on heterointerfaces and the accelerated mass transfer by array structure, the obtained self-supporting (Co9S8/CoS)@SNC/SCWF electrode exhibits superior performance toward alkaline oxygen evolution reaction (OER) with an ultra-low overpotential of 274 mV at 1000 mA/cm2, a small Tafel slope of 48.84 mV/dec, and ultralong stability up to 100 h. Theoretical calculations show that interfacing Co9S8 with CoS can upshift the d-band center of the Co atoms and strengthen the interactions with oxygen intermediates, thereby favoring OER performance. Furthermore, the (Co9S8/CoS)@SNC/SCWF electrode shows outstanding rechargeability and stable cycle life in aqueous Zn-air batteries with a peak power density of 201.3 mW/cm2, exceeding the commercial RuO2 and Pt/C hybrid catalysts. This work presents a promising strategy for the design of high-current-density OER electrocatalysts from sustainable wood fiber resources, thus promoting their practical applications in the field of electrochemical energy storage and conversion.
Aqueous proton batteries (APBs) embody a compelling alternative in the realm of economical and reliable energy technologies by virtue of their distinctive "Grotthuss mechanism". Sustainable production and adjustable molecular structure make organic polymers a promising choice for APB electrodes. However, inadequate proton-storage redox capability currently hinders their practical implementation. To address this issue, we introduce a pioneering phenazine-conjugated polymer (PPZ), synthesized through a straightforward polymerization process, marking its debut in APB applications. The inclusion of N-heteroaromatic fused-ring in the extended π-conjugated framework not only prevents the dissolution of redox-active units but also refines the energy bandgap and electronic properties, endowing the PPZ polymer with both structural integrity and enhanced redox activity. Consequently, the PPZ polymer as an electrode material achieves a remarkable proton-storage capacity of 211.5 mAh/g, maintaining a notable capacity of 158.3 mAh/g even under a high rate of 8 A/g with a minimal capacity fade of merely 0.00226% per cycle. The rapid, stable and impressive redox behavior is further elucidated through in-situ techniques and theoretical calculations. Ultimately, we fabricate an APB device featuring satisfactory electrochemical attributes with an extraordinary longevity over 10,000 cycles, thereby affirming its auspicious potential for eminent applications.
Developing effective strategy for constructing the electrocatalysts enable tri-functional electrocatalytic activity of hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is the premise to achieve both the zinc-air battery (ZAB) and overall water splitting. Herein, we utilize density functional theory to calculate the cobalt nitride (CoxN, x = 1, 2, 4, 5.47) system, revealing that the Co5.47N maybe exhibits a tri-functional activity due to the diverse valence states and high-density d-electron state of Co site. Furthermore, the electron of Co site is further delocalized by the electronic compensation effect of vanadium nitride (VN), thus improving the intermediates absorption and electrocatalytic activity. Accordingly, the Co5.47N/VN heterojunction is designed and synthesized via an electrospinning and a subsequent pyrolysis route. As expected, it displays excellent HER, OER, and ORR activity in alkaline electrolyte, which can be applied to assemble ZAB with a high power density of 207 mW/cm2 and overall water splitting system only requires a lower voltage of 1.53 V to achieve 10 mA/cm2. The electron regulation effect of VN makes the Co valence state decrease in the reduction reaction whereas increase in the oxidization reaction as evidenced by quasi-operando XPS analyses. Importantly, two ZABs connected in series could drive overall water splitting, indicating the potential application in renewable energy technologies.
Metal-organic frameworks (MOFs) provide great prospective in the photodegradation of pollutants. Nevertheless, the poor separation and recovery hamper their pilot- or industrial-scare applications because of their microcrystalline features. Herein, this challenge can be tackled by integrating Cu-MOFs into an alginate substrate to offer environmentally friendly, sustainable, facile separation, and high-performance MOF-based hydrogel photocatalysis platforms. The CuII-MOF 1 and CuI-MOF 2 were initially synthesized through a direct diffusion and single-crystal to single-crystal (SCSC) transformation method, respectively, and after the immobilization into alginate, more effective pollutant decontamination was achieved via the synergistic effect of the adsorption feature of hydrogel and in situ photodegradation of Cu-MOFs. Specifically, Cu-MOF-alginate composites present an improved and nearly completed Cr(VI) elimination at a short time of 15–25 min. Additionally, the congo red (CR) decolorization can be effectively enhanced in the presence of Cr(VI), and 1-alginate showed superior simultaneous decontamination efficiency of CR and Cr(VI) with 99% and 78%, respectively. Furthermore, Cu-MOF-alginate composites can maintain a high pollutant removal after over 10 continuous cycles (95% for Cr(VI) after 14 runs, and 90% for CR after 10 runs). Moreover, the Cr(VI)/CR degradation mechanism for Cu-MOF-alginate composite was investigated.
Cu-based metal-organic frameworks (MOFs) are widely employed in CO2 reduction reactions (CO2RR). Mostly, the in-situ reconstructed derivatives such as Cu or Cu oxides during CO2RR are regarded as the catalytic active center for the formation of catalytic products. However, in many cases, the pristine MOFs still exist during the catalytic process, the key role of these pristine MOFs is often ignored in revealing the catalytic mechanism. Here, we designed two Cu(imidazole) with different coordination environments, namely CuN2 and Cu2N4 for CO2RR. The structures of the two MOFs were still remained after the catalytic reaction. We discovered that the pristine MOFs served as activation catalysts for converting CO2 into CO. Sequentially, the Cu-based derivatives, in the two cases, Cu(111) converted the CO into C2+ products. The CuN2 with more exposed Cu-N centers showed a higher FECO and a higher final FEC2+ than Cu2N4. This auto-tandem catalytic mechanism was supported by electrocatalytic performance, TPD-CO, HRTEM, SAED, XPS, in-situ XANES and XES and DFT computation. The auto-tandem catalytic mechanism provides a new route to design Cu-based MOF electrocatalysts for high product selectivity in CO2RR.
Listeria monocytogenes (LM) is a dangerous foodborne pathogen for humans. One emerging and validated method of indirectly assessing LM in food is detecting 3-hydroxy-2-butanone (3H2B) gas. In this study, the synthesis of 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTMS) functionalized hierarchical hollow TiO2 nanospheres was achieved via precise controlling of solvothermal reaction temperature and post-grafting route. The sensors based on as-prepared materials exhibited excellent sensitivity (480 Hz@50 ppm), low detection limit (100 ppb), and outstanding selectivity. Moreover, the evaluation of LM with high sensitivity and specificity was achieved using the sensors. Such stable three-dimensional spheres, whose distinctive hierarchical and hollow nanostructure simultaneously improved both sensitivity and response/recovery speed dramatically, were spontaneously assembled by nanosheets. Meanwhile, the moderate loadings of AAPTMS significantly improved the selectivity of sensors. Then, the gas-sensing mechanism was explored by utilizing thermodynamic investigation, Gaussian 16 software, and in situ diffuse reflectance infrared transform spectroscopy, illustrating the weak chemisorption between the -NH- group and 3H2B molecules. These portable sensors are promising for real-time assessment of LM at room temperature, which will make a magnificent contribution to food safety.
Shape control of nickel sulfide (NiS2) catalysts is beneficial for boosting their catalytic performances, which is vital to their practical application as a class of advanced non-noble electro-catalysts. However, precisely controlling the formation kinetics and fabricate ultrathin NiS2 nanostructures still remains challenge. Herein, we provide an injection rate-mediated method to fabricate ultrathin NiS2 nanocages (HNCs) with hierarchical walls, high-density lattice defects and abundant grain boundaries (GBs). Through mechanism analysis, we find the injection rate determines the concentration of S2− in the steady state and thus control the growth pattern, leading to the formation of NiS2 HNCs at slow etching kinetics and NiCo PBA@NiS2 frames at fast etching kinetics, respectively. Benefiting from the ultrathin and hierarchical walls that minimize the mass transport restrictions, the high-density lattice defects and GBs that offer abundant unsaturated reaction sites, the NiS2 HNCs exhibit obviously enhanced electrocatalytic activity and stability toward OER, with overpotential of 255 mV to reach 10 mA/cm2 and a Tafel slope of 27.44 mV/dec, surpassing the performances of NiCo PBA@NiS2 frames and commercial RuO2.
Mn-based P2-type oxides are considered as promising cathodes for Na-ion batteries; however, they face significant challenges, including structural degradation when charged at high cutoff voltages and structural changes upon storing in a humid atmosphere. In response to these issues, we have designed an oxide with co-doping of Cu and Al which can balance both cost and structural stability. The redox reaction of Cu2+/3+ can provide certain charge compensation, and the introduction of Al can further suppress the Jahn-Teller effect of Mn, thereby achieving superior long-term cycling performance. The ex-situ XRD testing indicates that Cu/Al co-doping can effectively suppress the phase transition of P2-O2 at high voltage, thereby explaining the improvement in electrochemical performance. DFT calculations reveal a high chemical tolerance to moisture, with lower adsorption energy for H2O compared to pure Na0.67Cu0.25Mn0.75O2. A representative Na0.67Cu0.20Al0.05Mn0.75O2 cathode demonstrates impressive reversible capacities of 148.7 mAh/g at 0.2 C, along with a remarkable capacity retention of 79.1% (2 C, 500 cycles).
Environmentally friendly slow-release fertilizers are highly desired in sustainable agriculture. Encapsulating fertilizers can routinely achieve controlled releasing performances but suffers from short-term effectiveness or environmental unfriendliness. In this work, a bio-derived shellac incorporated with poly-dodecyl trimethoxysilane (SL-PDTMS) capsule was developed for long-term controlled releasing urea. Due to enhanced hydrophobicity and thus water resistance, the SL-PDTMS encapsulated urea fertilizer (SPEU) demonstrated a long-term effectiveness of 60 d, compared with SL encapsulated urea fertilizer (SEU, 30 d) and pure urea fertilizer (U, 5 min). In addition, SPEU showed a broad pH tolerance from 5.0 to 9.0, covering most various soil pH conditions. In the pot experiments, promoted growth of maize seedlings was observed after applying SPEU, rendering it promising as a high-performance controlled-released fertilizer.
Carbon monoxide (CO) is a crucial gaseous signaling molecule that regulates various physiological and pathological processes, and may exert an anti-inflammatory and protective role in drug-induced liver injury (DILI). Despite this, understanding the exact relationship between CO and the occurrence and development of DILI remains challenging. Hence, there is an urgent need to develop a reliable and robust tool for the rapid visual detection and assessment of CO in this context. Herein, we presented a novel near-infrared (NIR) fluorescent nanoprobe with aggregation-induced emission (AIE) properties and excited-state intramolecular proton transfer (ESIPT) characteristics for the detection and imaging of CO both in vitro and in vivo. Simultaneously, the nanoprobe enables self-assembly form nanoaggregates in aqueous media with high biocompatible, which can sense CO in situ through the conversion of yellow-to-red fluorescence facilitated aggregation-induced dual-color fluorescence. What is more, this nanoprobe shows ratiometric respond to CO, which demonstrates excellent stability, high sensitivity (with a detection limit of 12.5 nmol/L), and superior selectivity. Crucially, this nanoprobe enables the visual detection of exogenous and endogenous CO in living cells and tissues affected by DILI, offering a user-friendly tool for real-time visualization of CO in living system. Hence, it holds great promise in advancing our understanding of CO's role.
This study presents an approach to enhanced cancer immunotherapy through the in situ synthesis of potassium permanganate (KMnO4) derived manganese dioxide (MnO2) micro/nano-adjuvants. Addressing the limitations of traditional immunotherapy due to patient variability and the complexity of the tumor microenvironment, our research establishes KMnO4 as a potent immunomodulator that enhances the efficacy of anti-programmed death-ligand 1 (αPD-L1) antibodies. The in situ synthesized MnO2 adjuvants in the tumor exhibit direct interactions with biological systems, leading to the reduction of MnO2 to Mn2+ within the tumor, and thereby improving the microenvironment for immune cell activity. Our in vitro and in vivo models demonstrate KMnO4’s capability to induce concentration-dependent cytotoxicity in tumor cells, triggering DNA damage and apoptosis. It also potentiates immunogenic cell death by upregulating calreticulin and high mobility group box 1 (HMGB1) on the cell surface. The combination of KMnO4 with αPD-L1 antibodies substantially inhibits tumor growth, promotes dendritic cell maturation, and enhances CD8+ T cell infiltration, resulting in a significant phenotypic shift in tumor-associated macrophages towards a pro-inflammatory M1 profile. Our findings advocate for further research into the long-term efficacy of KMnO4 and its application in diverse tumor models, emphasizing its potential to redefine immune checkpoint blockade therapy and offering a new vista in the fight against cancer.
Crucial for mediating inflammation and the perception of pain, the ion channel known as transient receptor potential ankyrin 1 (TRPA1) holds significant importance. It contributes to the increased production of cytokines in the inflammatory cells of cartilage affected by osteoarthritis and represents a promising target for the treatment of this condition. By leveraging the unique advantages of liposomes, a composite microsphere drug delivery system with stable structural properties and high adaptability can be developed, providing a new strategy for osteoarthritis (OA) drug therapy. The liposomes as drug reservoirs for TRPA1 inhibitors were loaded into hyaluronic acid methacrylate (HAMA) hydrogels to make hydrogel microspheres via microfluidic technology. An in vitro inflammatory chondrocyte model was established with interleukin-1β (IL-1β) to demonstrate HAMA@Lipo@HC's capabilities. A destabilization of the medial meniscus (DMM) mouse model was also created to evaluate the efficacy of intra-articular injections for treating OA. HAMA@Lipo@HC has a uniform particle-size distribution and is injectable. The drug encapsulation rate was 64.29% ± 2.58%, with a sustained release period of 28 days. Inhibition of TRPA1 via HC-030031 effectively alleviated IL-1β-induced chondrocyte inflammation and matrix degradation. In DMM model OA mice, microspheres showed good long-term sustained drug release properties, improved joint inflammation microenvironment, reduced articular cartilage damage and decreased mechanical nociceptive threshold. This research pioneers the creation of a drug delivery system tailored for delivery into the joint cavity, focusing on TRPA1 as a therapeutic target for osteoarthritis. Additionally, it offers a cutting-edge drug delivery platform aimed at addressing diseases linked to inflammation.
Postoperative recurrence and metastasis are still the main challenges of cancer therapy. Tumor vaccines that induce potent and long-lasting immune activation have great potential for postoperative cancer therapy. However, the clinical effects of therapeutic tumor vaccines are unsatisfactory due to immune escape caused by the lack of immunogenicity after surgery and the local fibrosis barrier of the tumor which limits effector T cell infiltration. To overcome these challenges, we developed an injectable hydrogel-based tumor vaccine, RATG, which contains whole tumor cell lysates (TCL), Toll-like receptor (TLR) 7/8 agonist imiquimod (R837) and an antifibrotic drug ARV-825. TCL and R837 were loaded onto the hydrogel to achieve a powerful reservoir of antigens and adjuvants that induced potent and lasting immune activation. More importantly, ARV-825 could be slowly and sustainably released in the tumor resection cavity to downregulate α-smooth muscle actin (α-SMA) and collagen levels, disintegrate fibrosis barriers and promote T cell infiltration after immune activation to reduce immune escape. In addition, ARV-825 also directly acted on the remaining tumor cells to degrade bromodomain-containing protein 4 (BRD4) which is a critical epigenetic reader overexpressed in tumor cells, inhibiting tumor cell migration and invasion. Therefore, our injectable hydrogel created a powerful immune niche in postoperative tumor resection cavity, significantly enhancing the efficacy of tumor vaccines. Our strategy potently activates the immune system and disintegrates the fibrotic barrier of residual tumors with immune microenvironment remodeling in situ, showing anti-recurrence and anti-metastatic effects, and provides a new paradigm for postoperative treatment of tumors.
Efficient electrocatalysts for oxygen reduction reaction (ORR) show significant importance for advancing the performance and affordability of proton exchange membrane fuel cells and other energy conversion devices. Herein, PtCo3 nanoalloys dispersed on a carbon black support, were prepared using ultrafast Joule heating method. By tuning the heating modes, such as high-temperature shock and heating for 2 s, two kinds of PtCo3 nanoalloys with varying crystallinities were obtained, referred to as PtCo3HTS (average size of 5.4 nm) and PtCo3HT-2 s (average size of 6.4 nm), respectively. Impressively, PtCo3HTS exhibited superior electrocatalytic ORR activity and stability (E1/2 = 0.897 V vs. RHE and 36 mV negative shift after 50, 000 cycles), outperforming PtCo3HT-2 s (E1/2 = 0.872 V and 16.2 mV negative shift), as well as the commercial Pt/C (20 wt%) catalyst (E1/2 = 0.847 V and 21.0 mV negative shift). The enhanced ORR performance of PtCo3HTS may be attributed to its low crystallinity, which results in an active local electronic structure and chemical state, as confirmed by X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS) analyses. The ultrafast Joule heating method showed great potential for crystallinity engineering, offering a promising pathway to revolutionize the manufacturing of cost-effective and environmentally friendly catalysts for clean energy applications.
Diseases associated with bacterial infection, especially those caused by gram-negative bacteria, have been posing a serious threat to human health. Photodynamic therapy based on aggregation-induced emission (AIE) photosensitizer have recently emerged and provided a promising approach for bacterial discrimination and efficient photodynamic antimicrobial applications. However, they often suffer from the shorter excitation wavelength and lower molar extinction coefficients in the visible region, severely limiting their further applications. Herein, three novel BF2-curcuminoid-based AIE photosensitizers, TBBC, TBC and TBBC-C8, have been rationally designed and successfully developed, in which OCH3- and OC8H17-substituted tetraphenylethene (TPE) groups serve as both electron donor (D) and AIE active moieties, BF2bdk group functions as electron acceptor (A), and styrene (or ethylene) group as π-bridge in this D-π-A-π-D system, respectively. As expected, these resulting BF2-curcuminoids presented solvent-dependent photophysical properties with large molar extinction coefficients in solutions and excellent AIE properties. Notably, TBBC showed an effective singlet oxygen generation efficiency thanks to the smaller singlet-triplet energy gap (ΔEST), and remarkable photostability under green light exposure at 530 nm (8.9 mW/cm2). More importantly, TBBC was demonstrated effectiveness in selective staining and photodynamic killing of Escherichia coli (E. coli) in vitro probably due to its optimal molecular size compared with TBC and TBBC-C8. Therefore, TBBC will have great potential as a novel AIE photosensitizer to apply in the discrimination and selective sterilization between Gram-positive and Gram-negative bacteria.
Acute lung injury (ALI) is a serious clinical condition with a high mortality rate. Oxidative stress and inflammatory responses play pivotal roles in the pathogenesis of ALI. ONOO− is a key mediator that exacerbates oxidative damage and microvascular permeability in ALI. Accurate detection of ONOO− would facilitate early diagnosis and intervention in ALI. Near-infrared fluorescence (NIRF) probes offer new solutions due to their sensitivity, depth of tissue penetration, and imaging capabilities. However, the developed ONOO− fluorescent probes face problems such as interference from other reactive oxygen species and easy intracellular diffusion. To address these issues, we introduced an innovative self-immobilizing NIRF probe, DCI2F-OTf, which was capable of monitoring ONOO− in vitro and in vivo. Importantly, leveraging the high reactivity of the methylene quinone (QM) intermediate, DCI2F-OTf was able to covalently label proteins in the presence of ONOO−, enabling in situ imaging. In mice models of ALI, DCI2F-OTf enabled real-time imaging of ONOO− levels and found that ONOO− was tightly correlated with the progression of ALI. Our findings demonstrated that DCI2F-OTf was a promising chemical tool for the detection of ONOO−, which could help to gain insight into the pathogenesis of ALI and monitor treatment efficacy.
Glioma is a severe malignant brain tumor marked by an exceedingly dire prognosis and elevated incidence of recurrence. The resilience of such tumors to chemotherapeutic agents, coupled with the formidable obstacle the blood-brain barrier (BBB) presents to most pharmacological interventions are major challenges in anti-glioma therapy. In an endeavor to surmount these impediments, we have synergized pH-sensitive nanoparticles carrying doxorubicin and apatinib to amplify the anti-neoplastic efficacy with cyclic arginine–glycine–aspartate acid (cRGD) modification. In this study, we found that the combination of doxorubicin (DOX) and apatinib (AP) showed a significant synergistic effect, achieved through cytotoxicity and induction of apoptosis, which might be due to the increased intracellular uptake of DOX following AP treatment. Besides, polycaprolactone-polyethylene glycol-cRGD (PCL-PEG-cRGD) drug carrier could cross the BBB by its targeting ability, and then deliver the drug to the glioma site via pH-responsive release, increasing the concentration of the drugs in the tumor. Meanwhile, DOX/AP-loaded PCL-PEG-cRGD nanoparticles effectively inhibited cell proliferation, enhanced glioma cell apoptosis, and retarded tumor growth in vivo. These results collectively identified DOX/AP-loaded PCL-PEG-cRGD nanoparticles as a promising therapeutic candidate for the treatment of glioma.
Insufficient endogenous H2O2 for generation of hydroxyl radicals (•OH) has strikingly compromised anti-tumor benefits of ferroptosis. Herein, we develop a H2O2 self-supplying nanoparticle based on a pH-responsive lipopeptide C18-pHis10. Inspired by the coordinate pattern of hemoglobin binding heme, Fe2+ and tetrakis(4-carboxyphenyl)porphyrin (TCPP) were delicately encapsulated by formation of coordination compounds with His. Ascorbgyl palmitate (AscP) was also incorporated into the nanoparticles for generation of H2O2 by reduction 1O2 produced from TCPP, meanwhile prevented Fe2+ from being oxidized. The protonation of pHis in acidic endo-lysosome induced the breakage of Fe2+/His/TCPP coordinate interactions, leading to accelerated release of payloads and the following escape to cytoplasm. Upon laser irradiation, TCPP produces excessive 1O2 followed by conversion to H2O2 in the presence of AscP, which is further catalyzed to lethal •OH by Fe2+ via Fenton reaction. The self-supplying H2O2 was found to result significantly higher accumulation of lipid peroxides and more effective tumor inhibition. Overall, this work sheds new a light on H2O2 self-supplying strategy to enhance ferroptosis by taking advantage of 1O2 generated by photodynamic therapy (PDT).
D-D'-A type aza-borondipyrromethenes (aza-BODIPYs) were prepared by Suzuki cross-coupling reaction. Photothermal conversion efficiency of self-assemble aza-BODIPY-based nanoparticles (DA-azaBDP-NPs) with NIR-II emission (λem = 1065 nm) was 37.2% under near infrared (NIR) irradiation, and the outstanding cytotoxicity was triggered by coexistence of DA-azaBDP-NPs and the NIR irradiation, with the decrease of glioblastoma migration and the inhibition of glioblastoma proliferation. DA-azaBDP-NPs could promote glioblastoma autophagy and accelerate the process of cell death. The photothermal therapy (PTT) of DA-azaBDP-NPs can effectively induce glioblastoma death by apoptosis under the NIR irradiation, which is highly promising to be applied in vivo experiments of brain.
Singlet oxygen (1O2), as the primary reactive oxygen species in photodynamic therapy, can effectively induce excessive oxidative stress to ablate tumors and kill germs in clinical treatment. However, monitoring endogenous 1O2 is greatly challenging due to its extremely short lifetime and high reactivity in biological condition. Herein, we report an ultra-high signal-to-ratio near-infrared chemiluminescent probe (DCM-Cy) for the precise detection of endogenous 1O2 during photodynamic therapy (PDT). The methoxy moiety was removed from enolether unit in DCM-Cy to suppress the potential self-photooxidation reaction, thus greatly eliminating the photoinduced background signals during PDT. Additionally, the compact cyclobutane modification of DCM-Cy resulted in a significant 6-fold increase in cell permeability compared to conventional adamantane-dioxane probes. Therefore, our "step-by-step" strategy for DCM-Cy addressed the limitations of traditional chemiluminescent (CL) probes for 1O2, enabling effectively tracking of endogenous 1O2 level changes in living cells, pathogenic bacteria and mice in PDT.
Interstitial hypertension and extracellular matrix (ECM) barriers imposed by cancer-associated fibroblasts (CAFs) at the tumor site significantly impede the retention of intratumorally administered oncolytic viruses (OVs) as well as their efficacy in infecting and eradicating tumor cells. Herein, a stable, controllable, and easily prepared hydrogel was developed for employing a differential release strategy to deliver OVs. The oncolytic herpes simplex virus-2 (oH2) particles were loaded within sodium alginate (ALG), together with the small molecule drug PT-100 targeting CAFs. The rapid release of PT-100 functions as an anti-CAFs agent, reducing ECM, and alleviating interstitial pressure at the tumor site. Consequently, the delayed release of oH2 could more effectively invade and eradicate tumor cells while also facilitating enhanced infiltration of immune cells into the tumor microenvironment, thereby establishing an immunologically favorable milieu against tumors. This approach holds significant potential for achieving highly efficient oncolytic virus therapy with minimal toxicity, particularly in tumors rich in stromal components.
Constructing multi-dimensional hydrogen bond (H-bond) regulated single-molecule systems with multi-emission remains a challenge. Herein, we report the design of a new excited-state intramolecular proton transfer (ESIPT) featured chromophore (HBT-DPI) that shows flexible emission tunability via the multi-dimensional regulation of intra- and intermolecular H-bonds. The feature of switchable intramolecular H-bonds is induced via incorporating several hydrogen bond acceptors and donors into one single HBT-DPI molecule, allowing the "turn on/off" of ESIPT process by forming isomers with distinct intramolecular H-bonds configurations. In response to different external H-bonding environments, the obtained four types of crystal/cocrystals vary in the contents of isomers and the molecular packing modes, which are mainly guided by the intermolecular H-bonds, exhibiting non-emissive features or emissions ranging from green to orange. Utilizing the feature of intermolecular H-bond guided molecular packing, we demonstrate the utility of this fluorescent material for visualizing hydrophobic/hydrophilic areas on large-scale heterogeneous surfaces of modified poly(1,1-difluoroethylene) (PVDF) membranes and quantitatively estimating the surface hydrophobicity, providing a new approach for hydrophobicity/hydrophilicity monitoring and measurement. Overall, this study represents a new design strategy for constructing multi-dimensional hydrogen bond regulated ESIPT-based fluorescent materials that enable multiple emissions and unique applications.
Photodynamic therapy (PDT) has emerged as a promising approach for tumor treatment due to its non-invasiveness and high selectivity. However, the off-target activation of phototoxicity and the limited availability of tumor-specific biomarkers pose challenges for effective PDT. Here, we present the development of a novel ratiometric near-infrared-Ⅱ (NIR-Ⅱ) fluorescent organic nanoprobe, BTz-IC@IR1061, which responds specifically to hypochlorite (HClO) within tumors. This nanoprobe allows ratiometric fluorescence imaging to monitor and guide activated tumor PDT. BTz-IC@IR1061 nanoparticles were synthesized by codoping the small molecule dye BTz-IC, which generates reactive oxygen species (ROS), with the commercial dye IR1061. The presence of HClO selectively activates the fluorescence and photodynamic properties of BTz-IC while destroying IR1061, enabling controlled release of ROS for tumor therapy. We demonstrated the high selectivity of the nanoprobe for HClO, as well as its excellent photostability, photoacoustic imaging capability, and photothermal effects. Furthermore, in vivo studies revealed effective tumor targeting and remarkable tumor growth inhibition through tumor-activated PDT. Our findings highlight the potential of BTz-IC@IR1061 as a promising tool for tumor-specific PDT, providing new opportunities for precise and controlled cancer therapy.
The bioactive constituents found in natural products (NPs) are crucial in protein-ligand interactions and drug discovery. However, it is difficult to identify ligand molecules from complex NPs that specifically bind to target protein, which often requires time-consuming and labor-intensive processes such as isolation and enrichment. To address this issue, in this study we developed a method that combines ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MS) with molecular dynamics (MD) simulation to identify and observe, rapidly and efficiently, the bioactive components in NPs that bind to specific protein target. In this method, a specific protein target was introduced online using a three-way valve to form a protein-ligand complex. The complex was then detected in real time using high-resolution MS to identify potential ligands. Based on our method, only 10 molecules from green tea (a representative natural product), including the commonly reported epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), as well as the previously unreported eepicatechin (4β→8)-epigallocatechin 3-O-gallate (EC-EGCG) and eepiafzelechin 3-O-gallate-(4β→8)-epigallocatechin 3-O-gallate (EFG-EGCG), were screened out, which could form complexes with Aβ1–42 (a representative protein target), and could be potential ligands of Aβ1–42. Among of them, EC-EGCG demonstrated the highest binding free energy with Aβ1–42 (−68.54 ± 3.82 kcal/mol). On the other side, even though the caffeine had the highest signal among green tea extracts, it was not observed to form a complex with Aβ1–42. Compared to other methods such as affinity selection mass spectrometry (ASMS) and native MS, our method is easy to operate and interpret the data. Undoubtedly, it provides a new methodology for potential drug discovery in NPs, and will accelerate the research on screening ligands for specific proteins from complex NPs.
The overuse of surfactants has made them well-known environmental pollutants. So far, it is still a challenge to simultaneously distinguish cationic, anionic, zwitterionic, nonionic surfactants and surfactants with similar structures based on traditional analytical techniques. We developed a high-throughput method for distinguishing various surfactants based on the adaptive emission profile as fingerprints (AEPF). The fluorescence response of the sensor was based on the interaction between surfactants and 1,3-diacetylpyrene (o-DAP) probe. The interaction affected the reversible conversion of free molecules and two aggregates in the solution, thereby changing the relative abundance and the fluorescence intensity ratio of two aggregates emitting different fluorescence. The o-DAP sensor can distinguish four types of surfactants (16 surfactants), especially surfactants of the same type with similar structures. The o-DAP sensor sensitively determined the critical micelle concentration (CMC) of 16 surfactants based on the interaction between o-DAP and surfactants. Additionally, the o-DAP sensor can detect and distinguish artificial vesicles made from different surfactants.
Severe traumatic bone healing relies on the involvement of growth factors. However, excessive supplementation of growth factors can lead to ectopic ossification and inflammation. In this study, utilizing the neural regulatory mechanism of bone regeneration, we have developed a multifunctional three dimensions (3D) printed scaffold containing both vasoactive intestinal peptide (VIP) and nerve growth factor (NGF) as an effective new method for achieving bone defect regeneration. The scaffold is provided by a controlled biodegradable and biomechanically matched poly(lactide-ethylene glycol-trimethylene carbonate) (PLTG), providing long-term support for the bone healing cycle. Factor loading is provided by peptide fiber-reinforced biomimetic antimicrobial extracellular matrix (ECM) (B-ECM) hydrogels with different release kinetics, the hydrogel guides rapid bone growth and resists bacterial infection at the early stage of healing. Physical and chemical characterization indicates that the scaffold has good structural stability and mechanical properties, providing an ideal 3D microenvironment for bone reconstruction. In the skull defect model, compared to releasing VIP or NGF alone, this drug delivery system can simulate a natural healing cascade of controllable release factors, significantly accelerating nerve/vascular bone regeneration. In conclusion, this study provides a promising strategy for implanting materials to repair bone defects by utilizing neuroregulatory mechanisms during bone regeneration.
Biomolecular condensates, also known as membraneless organelles, play a crucial role in cellular organization by concentrating or sequestering biomolecules. Despite their importance, synthetically mimicking these organelles using non-peptidic small organic molecules has posed a significant challenge. The present study reports the discovery of D008, a self-assembling small molecule that sequesters a unique subset of RNA-binding proteins. Analysis and screening of a comprehensive collection of approximately 1 million compounds in the Chinese National Compound Library (Shanghai) identified 44 self-assembling small molecules in aqueous solutions. Subsequent screening of the focused library, coupled with proteome analysis, led to the discovery of D008 as a small organic molecule with the ability to condensate a specific subset of RNA-binding proteins. In vitro experiments demonstrated that the D008-induced sequestration of RNA-binding proteins impeded mRNA translation. D008 may offer a unique opportunity for studying the condensations of RNA-binding proteins and for developing an unprecedented class of small molecules that control gene expression.
Diabetic kidney disease (DKD) is recognized as a severe complication in the development of diabetes mellitus (DM), posing a significant burden for global health. Major characteristics of DKD kidneys include tubulointerstitial oxidative stress, inflammation, excessive extracellular matrix deposition, and progressing renal fibrosis. However, current treatment options are limited and cannot offer enough efficacy, thus urgently requiring novel therapeutic approaches. Tetrahedral framework nucleic acids (tFNAs) are a novel type of self-assembled DNA nanomaterial with excellent structural stability, biocompatibility, tailorable functionality, and regulatory effects on cellular behaviors. In this study, we established an in vitro high glucose (HG)-induced human renal tubular epithelial cells (HK-2 cells) pro-fibrogenic model and explored the antioxidative, anti-inflammatory, and antifibrotic capacity of tFNAs and the potential molecular mechanisms. tFNAs not only effectively alleviated oxidative stress through reactive oxygen species (ROS)-scavenging and activating the serine and threonine kinase (Akt)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway but also inhibited the production of pro-inflammatory factors such as tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in diabetic HK-2 cells. Additionally, tFNAs significantly downregulated the expression of Collagen I and α-smooth muscle actin (α-SMA), two representative biomarkers of pro-fibrogenic myofibroblasts in the renal tubular epithelial-mesenchymal transition (EMT). Furthermore, we found that tFNAs exerted this function by inhibiting the Wnt/β-catenin signaling pathway, preventing the occurrence of EMT and fibrosis. The findings of this study demonstrated that tFNAs are naturally endowed with great potential to prevent fibrosis progress in DKD kidneys and can be further combined with emerging pharmacotherapies, providing a secure and efficient drug delivery strategy for future DKD therapy.
A computer-assisted chemical investigation of an intriguing photoreaction of norditerpenoids (3‒7) has been first reported, leading to not only their biomimetic conversion, but also the generation of several new products with uncommon 4,14-dioxabicyclo[10.2.1]pentadecane scaffold (8, 9, 12‒14). In bioassay, compounds 10 and 15 exhibited significant stimulation of GLP-1 secretion. This study has given an insight for the application of computational methods on the late-stage skeleton transformation of complex natural products towards new bioactive compounds.
Tumor blockade therapy inhibits tumor progression by cutting off essential supplies of nutrients, oxygen, and biomolecules from the surrounding microenvironments. Inspired by natural processes, tumor biomineralization has evolved due to its biocompatibility, self-reinforcing capability, and penetration-independent mechanism. However, the selective induction of tumor biomineralization using synthetic tools presents a significant challenge. Herein, a metabolic glycoengineering-assistant tumor biomineralization strategy was developed. Specifically, the azido group (N3) was introduced onto the cytomembrane by incubating tumor cells with glycose analog Ac4ManNAz. In addition, a bisphosphonate-containing polymer, dibenzocyclooctyne-poly(ethylene glycol)-alendronate (DBCO-PEG-ALN, DBPA) was synthesized, which attached to the tumor cell surface via "click chemistry" reaction between DBCO and N3. Subsequently, the bisphosphonate group on the cell surface chelated with positively charged ions in the microenvironments, triggering a consecutive process of biomineralization. This physical barrier significantly reduced tumor cell viability and mobility in a calcium ion concentration-dependent manner, suggesting its potential as an effective anti-tumor strategy for in vivo applications.
The aggressive nature and high mortality rate of lung cancer underscore the imperative need for early diagnosis of the disease. Thus, aminopeptidase N (APN), a potential biomarker for lung cancer, should be thoroughly investigated in this context. This report describes the development of HA-apn, a novel near-infrared fluorescent probe, specifically engineered for the sensitive detection of endogenous APN. Characterized by its high selectivity, straightforward molecular architecture, and suitable optical properties, including a long-wavelength emission at 835 nm and a large Stokes shift of 285 nm, HA-apn had high efficacy in identifying overexpressed APN in tumor cells, which shows its potential in pinpointing malignancies. To further validate its applicability and effectiveness in facilitating the direct and enhanced visualization of pulmonary alterations, an in situ lung cancer mouse model was employed. Notably, HA-apn was applied for in vivo imaging of APN activity in the lung cancer mouse model receiving the probe through aerosol inhalation, and rapid and precise diagnostic results were achieved within 30 min post-administration. Overall, HA-apn can be applied as an effective, non-intrusive tool for the rapid and accurate detection of pulmonary conditions.
[2+2]-Type cyclobutane derivatives comprise a large family of natural products with diverse molecular architectures. However, the structure elucidation of the cyclobutane ring, including its connection mode and stereochemistry, presents a significant challenge. Plumerubradins A–C (1–3), three novel iridoid glycoside [2+2] dimers featuring a highly functionalized cyclobutane core and multiple stereogenic centers, were isolated from the flowers of Plumeria rubra. Through biomimetic semisynthesis and chemical degradation of compounds 1–3, synthesis of phenylpropanoid-derived [2+2] dimers 7–10, combined with extensive spectroscopic analysis, single-crystal X-ray crystallography, and microcrystal electron diffraction experiments, the structures with absolute configurations of 1–3 were unequivocally elucidated. Furthermore, quantum mechanics-based 1H NMR iterative full spin analysis successfully established the correlations between the signal patterns of cyclobutane protons and the structural information of the cyclobutane ring in phenylpropanoid-derived [2+2] dimers, providing a diagnostic tool for the rapid structural elucidation of [2+2]-type cyclobutane derivatives.
Early recognition is key to improving the prognosis of ischemic stroke (IS), while available imaging methods tend to target events that have already undergone ischemia. A new method to detect early IS is urgently needed, as well as further study of its mechanisms. Viscosity and cysteine (Cys) levels of mitochondria have been associated with ferroptosis and IS. It is possible to identify IS and ferroptosis accurately and early by monitoring changes in mitochondrial Cys and viscosity simultaneously. In this work, a viscosity/Cys dual-responsive mitochondrial-targeted near-infrared (NIR) fluorescent probe (NVCP) was constructed for the precise tracking of IS using a two-dimensional design strategy. NVCP consists of a chromophore dyad containing diethylaminostyrene quinolinium rotor and chloro-sulfonylbenzoxadiazole (SBD-Cl) derivative with two easily distinguished emission bands (λem = 592 and 670 nm). NVCP performs the way of killing two birds with one stone, that is, the probe exhibits excellent selectivity and sensitivity for detecting viscosity and Cys in living cells with excellent biocompatibility and accurate mitochondrial targeting capability by dual channel imaging mode. In addition, NVCP recognized that the viscosity increases and Cys level decreases in cells when undergoing ferroptosis and oxygen-glucose deprivation (OGD) stress by confocal imaging, flow cytometry, and Western blot experiments. Treatment of ferroptosis inhibitors (ferrostatin-1 (Fer-1) and deferoxamine (DFO)) could reverse the variation tendency of viscosity and Cys. This is the first time that the relationship between ferroptosis and IS was identified through an analysis of Cys and viscosity. More importantly, the ischemic area was also instantly distinguished from normal tissues through fluorescence imaging of NVCP in vivo. The developed NIR dual-responsive probe NVCP toward viscosity and Cys could serve as a sensitive and reliable tool for tracking ferroptosis-related pathological processes during IS.
Photodynamic therapy (PDT) has received much attention in recent years. However, traditional photosensitizers (PSs) applied in PDT usually suffer from aggregation-caused quenching (ACQ) effect in H2O, single and inefficient photochemical mechanism of action (MoA), poor cancer targeting ability, etc. In this work, two novel Ru(Ⅱ)-based aggregation-induced emission (AIE) agents (Ru1 and Ru2) were developed. Both complexes exhibited long triplet excited lifetimes and nearly 100% singlet oxygen quantum yields in H2O. In addition, Ru1 and Ru2 displayed potent photo-catalytic reduced nicotinamide adenine dinucleotide (NADH) oxidation activity with turnover frequency (TOF) values of about 1779 and 2000 h−1, respectively. Therefore, both Ru1 and Ru2 showed efficient PDT activity towards a series of cancer cells. Moreover, Ru2 was further loaded in bovine serum albumin (BSA) to enhance the tumor targeting ability in vivo, and the obtained Ru2@BSA could selectively accumulate in tumor tissues and effectively inhibit tumor growth on a 4T1 tumor-bearing mouse model. So far as we know, this work represents the first report about Ru(Ⅱ) AIE agents that possess high singlet oxygen quantum yields and also potent photo-catalytic NADH oxidation activity, and may provide new ideas for rational design of novel PSs with efficient PDT activity.
Chemodynamic therapy (CDT), using Fenton agents to generate highly cytotoxic •OH from H2O2 has been demonstrated as a powerful anticancer method. However, the insufficient endogenous H2O2 in tumor cells greatly limited its therapeutic effect. Herein, we prepared a pH-responsive β-lapachone-loaded iron-polyphenol nanocomplex (LIPN) through a one-pot method. β-Lapachone in LIPN selectively enhanced H2O2 concentration in tumor cells, and ferrous ions cascadely generated abundant cytotoxic •OH. Therefore, LIPN with cascade amplification of reactive oxygen species (ROS) showed high chemodynamic cytotoxicity in tumor cells, efficiently improving the expression of damage-associated molecular patterns (DAMPs), and exerting strong immunogenic cell death (ICD). As a result, LIPN exhibited efficient tumor inhibition ability in 4T1 subcutaneous tumor model in vivo with great biocompatibility. Additionally, the infiltration of cytotoxic CD8+ T lymphocytes and inhibition of regulatory CD4+ FoxP3+ T lymphocytes in tumors demonstrated the activation of immunosuppressive tumor microenvironment by LIPN-induced ICD. Therefore, this work provided a new approach to enhance ICD of chemodynamic therapy through selective cascade amplification of ROS in cancer cells.
The typical wastewater treatment is focused on the photocatalytic efficiency in the degradation of organic pollutants, with little attention to the involved selectivity which may correlate with toxicant residues. Herein, an electron localization strategy for specific O2 adsorption/activation enabled by photothermal/pyroelectric effect and in situ constructed active centers of single-atom Co and oxygen vacancy (Co-OV) on the Co/BiOCl-OV photocatalyst was developed for photocatalytic degradation of glyphosate (GLP) wastewater of high performance/selectivity. Under full-spectrum-light irradiation, a high GLP degradation rate of 99.8% with over 90% C‒P bond-breaking selectivity was achieved within 2 h, while effectively circumventing toxicant residues such as aminomethylphosphonic acid (AMPA). X-ray absorption spectroscopy and relevant characterizations expounded the tailored anchoring of Co single atoms onto the BiOCl-OV carrier and photothermal/pyroelectric effect. The oriented formation of more •O2− on Co/BiOCl-OV could be achieved with the Co-OV coupled center that had excellent O2 adsorption/activation capacity, as demonstrated by quantum calculations. The formed unique Co-OV active sites could largely decrease the C‒P bond-breaking energy barrier, thus greatly improving the selectivity toward the initial C‒P bond scission and the activity in subsequent conversion steps in the directional photocatalytic degradation of GLP. The electron localization strategy by in situ constructing the coupled active centers provides an efficient scheme and new insights for the low-toxic photodegradation of organic pollutants containing C‒X bonds.
Lipids serve as fundamental constituents of cell membranes and organelles. Recent studies have highlighted the significance of lipids as biomarkers in the diagnosis of breast cancer. Although liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is widely employed for lipid analysis in complex samples, it suffers from limitations such as complexity and time-consuming procedures. In this study, we have developed dopamine-modified TiO2 nanoparticles (TiO2-DA) and applied the materials to assist the analysis of lipids by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The TiO2-DA can provide large specific surface area and acidic environment, well suited for lipid analysis. The method was initially validated using standard lipid molecules. Good sensitivity, reproducibility and quantification performance was observed. Then, the method was applied to the analysis of 90 serum samples from 30 patients with breast cancer, 30 patients with benign breast disease and 30 healthy controls. Five lipid molecules were identified as potential biomarkers for breast cancer. We constructed a classification model based on the MALDI-TOF MS signal of the 5 lipid molecules, and achieved high sensitivity, specificity and accuracy for the differentiation of breast cancer from benign breast disease and healthy control. We further collected another 60 serum samples from 20 healthy controls, 20 patients with benign breast disease and 20 patients with breast cancer for MALDI-TOF MS analysis to verify the accuracy of the classification model. This advancement holds great promise for the development of diagnostic models for other lipid metabolism-related diseases.
Boron neutron capture therapy (BNCT) has emerged as a promising treatment for cancers, offering a unique approach to selectively target tumor cells while sparing healthy tissues. Despite its clinical utility, the widespread use of fructose-BPA (F-BPA) has been hampered by its limited ability to penetrate the blood-brain barrier (BBB) and potential risks for patients with certain complications such as diabetes, hyperuricemia, and gout, particularly with substantial dosages. Herein, a series of novel BPA derivatives were synthesized. After the primary screening, geniposide-BPA (G-BPA) and salidroside-BPA (S-BPA) exhibited high water solubility, low cytotoxicity and safe profiles for intravenous injection. Furthermore, both G-BPA and S-BPA had demonstrated superior efficacy in vitro against the 4T1 cell line compared with F-BPA. Notably, S-BPA displayed optimal BBB penetration capability, as evidenced by in vitro BBB models and glioblastoma models in vivo, surpassing all other BPA derivative candidates. Meanwhile, G-BPA also exhibited enhanced performance relative to the clinical drug F-BPA. In brief, G-BPA and S-BPA, as novel BPA derivatives, demonstrated notable safety profiles and remarkable boron delivery capabilities, thereby offering promising therapeutic options for BNCT in the clinic.
Gallstones are a common disease worldwide, often leading to obstruction and inflammatory complications, which seriously affect the quality of life of patients. Research has shown that gallstone disease is associated with ferroptosis, lipid droplets (LDs), and abnormal levels of nitric oxide (NO). Fluorescent probes provide a sensitive and convenient method for detecting important substances in life systems and diseases. However, so far, no fluorescent probes for NO and LDs in gallstone disease have been reported. In this work, an effective ratiometric fluorescent probe LR-NH was designed for the detection of NO in LDs. With an anthracimide fluorophore and a secondary amine as a response site for NO, LR-NH exhibits high selectivity, sensitivity, and attractive ratiometric capability in detecting NO. Importantly, it can target LDs and shows excellent imaging ability for NO in cells and ferroptosis. Moreover, LR-NH can target the gallbladder and image NO in gallstone disease models, providing a unique and unprecedented tool for studying NO in LDs and gallbladder.
Photocatalytic overall water splitting is a promising method for producing clean hydrogen energy, but faces challenges such as low light utilization efficiency and high charge carrier recombination rates. This study demonstrates that dielectric Mie resonance in TiO2 hollow nanoshells can enhance electric field intensity and increase light absorption through resonant energy transfer, compared to crushed TiO2 nanoparticles. The Mie resonance effect was confirmed through fluorescence spectra, photo-response current measurements, photocatalytic water splitting experiments, and Mie calculation. The incident electric-field amplitude was doubled in hollow nanoshells, allowing for increased light trapping. Additionally, the spatially separated Pt and RuO2 cocatalysts on the inner and outer surfaces facilitated the separation of photoinduced electrons and holes. Pt@TiO2@RuO2 hollow nanoshells exhibited superior photocatalytic water splitting performance, with a stable H2 generation rate of 50.1 µmol g−1 h−1 and O2 evolution rate of 25.1 µmol g−1 h−1, outperforming other nanostructures such as TiO2, Pt@TiO2, and TiO2@RuO2 hollow nanoshells. This study suggests that dielectric Mie resonance and spatially-separated cocatalysts offer a new approach to simultaneously enhance light absorption and charge carrier transfer in photocatalysis.
Traditional Pt/C electrode materials are prone to corrosion and detachment during H2S detection, leading to a decrease in fuel cell-type sensor performance. Here, a high-performance H2S sensor based on Pt loaded Ti3C2 electrode material with -O/-OH terminal groups was designed and prepared. Experimental tests showed that the Pt/Ti3C2 sensor has good sensitivity (0.162 µA/ppm) and a very low detection limit to H2S (10 ppb). After 90 days of stability testing, the response of the Pt/Ti3C2 sensor shows a smaller decrease of 2% compared to that of the Pt/C sensor (22.9%). Meanwhile, the sensor also has high selectivity and repeatability. The density functional theory (DFT) calculation combined with the experiment results revealed that the improved H2S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti3C2 via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti3C2, ultimately prolonging the sensor’s service life. Furthermore, the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H2S on Pt/Ti3C2 surface, greatly enhance the ability to generate protons and effectively transfer charges, realizing good sensitivity and high selectivity of the sensor. The sensor works at room temperature, making it very promising in the field of H2S detection in future.
The addition of cold flow improvers (CFIs) is considered as the optimum strategy to improve the cold flow properties (CFPs) of diesel fuels, but this strategy is always limited by the required large dosage. To obtain low-dosage and high-efficiency CFIs for diesel, 1,2,3,6-tetrahydrophthalic anhydride (THPA) was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylate-trans anethole copolymers (C14MC-TA). The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride (C14MC-TA-THPA) were synthesized and compared with the binary copolymers of C14MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride (C14MC-THPA). Results showed that C14MC -THPA achieved the best depressive effects on the cold filter plugging point (CFPP) and solid point (SP) by 11 ℃ and 16 ℃ at a dosage of 1250 mg/L and monomer ratio of 6:1, while 1500 mg/L C14MC-TA (1:1) reached the optimal depressive effects on the CFPP and SP by 12 ℃ and 18 ℃. THPA introduction significantly improved the depressive effects of C14MC-TA. Lower dosages of C14MC-TA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C14MC-TA and C14MC-THPA. When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L, the improvement effect of C14MC-TA-THPA on diesel reached the optimum level, and the CFPP and SP were reduced by 13 ℃ and 19 ℃, respectively. A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios, dosages, and depressive effects of CFIs in diesel. Surface analysis results showed that C14MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L, and the CFPP and SP decreased by 14 ℃ and 19 ℃, respectively. The predicted results were consistent with the actual ones. Additionally, the improvement mechanism of these copolymers in diesel was also explored.
Simultaneous degradation and detoxification during pharmaceutical and personal care product removal are important for water treatment. In this study, sodium niobate nanocubes decorated with graphitic carbon nitride (NbNC/g-C3N4) were fabricated to achieve the efficient photocatalytic degradation and detoxification of ciprofloxacin (CIP) under simulated solar light. NaNbO3 nanocubes were in-situ transformed from Na2Nb2O6·H2O via thermal dehydration at the interface of g-C3N4. The optimized NbNC/g-C3N4–1 was a type-Ⅰ heterojunction, which showed a high conduction band (CB) level of −1.68 eV, leading to the efficient transfer of photogenerated electrons to O2 to produce primary reactive species, •O2−. Density functional theory (DFT) calculations of the density of states indicated that C 2p and Nb 3d contributed to the CB, and 0.37 e– transferred from NaNbO3 to g-C3N4 in NbNC/g-C3N4 based on the Mulliken population analysis of the built-in electric field intensity. NbNC/g-C3N4–1 had 3.3- and 2.3-fold of CIP degradation rate constants (k1 = 0.173 min−1) compared with those of pristine g-C3N4 and NaNbO3, respectively. In addition, N24, N19, and C5 in CIP with a high Fukui index were reactive sites for electrophilic attack by •O2−, resulting in the defluorination and ring-opening of the piperazine moiety of the dominant degradation pathways. Intermediate/product identification, integrated with computational toxicity evaluation, further indicated a substantial detoxification effect during CIP degradation in the photocatalysis system.
Rational tuning of crystallographic surface and metal doping were effective to enhance the catalytic performance of metal organic frameworks, but limited work has been explored for achieving modulation of crystal facets and metal doping in a single system. MIL-68(In) was promising for photocatalytic applications due to its low toxicity and excellent photoresponsivity. However, its catalytic activity was constrained by severe carrier recombination and a lack of active sites. Herein, increased (001) facet ratio and active sites exposure were simultaneously realized by cobalt doping in MIL-68(In) through a one-pot solvothermal strategy. Optimized MIL-68(In/Co)-2.5 exhibited remarkable catalytic performance in comparison with pristine MIL-68(In) and other MIL-68(In/Co). The reaction kinetic constant and degradation efficiency of MIL-68(In/Co) were approximately twice and 17% higher than the pristine MIL-68(In) in 36 min reaction, respectively. Density functional theory calculations revealed that Co dopant could modulate the orientation of MIL-68(In) facets, facilitate the exchange of electrons and reduce the adsorption energy of peroxymonosulfate (PMS). This work provides a novel pathway for improvement of In-based MOFs in PMS/vis system, it also promotes the profound comprehension of the correlation between crystal facet regulation and catalytic activation in the PMS/vis system.
As antibiotic pollutants cannot be incompletely removed by conventional wastewater treatment plants, ultraviolet (UV) based advanced oxidation processes (AOPs) such as UV/persulfate (UV/PS) and UV/chlorine are increasingly concerned for the effective removal of antibiotics from wastewaters. However, the specific mechanisms involving degradation kinetics and transformation mechanisms are not well elucidated. Here we report a detailed examination of SO4•−/Cl•-mediated degradation kinetics, products, and toxicities of sulfathiazole (ST), sarafloxacin (SAR), and lomefloxacin (LOM) in the two processes. Both SO4•−/Cl•-mediated transformation kinetics were found to be dependent on pH (P < 0.05), which was attributed to the disparate reactivities of their individual dissociated forms. Based on competition kinetic experiments and matrix calculations, the cationic forms (H2ST+, H2SAR+, and H2LOM+) were more highly reactive towards SO4•− in most cases, while the neutral forms (e.g., HSAR0 and HLOM0) reacted the fastest with Cl• for the most of the antibiotics tested. Based on the identification of 31 key intermediates using tandem mass spectrometry, these reactions generated different products, of which the majority still retained the core chemical structure of the parent compounds. The corresponding diverse transformation pathways were proposed, involving S−N breaking, hydroxylation, defluorination, and chlorination reactions. Furthermore, the toxicity changes of their reaction solutions as well as the toxicity of each intermediate were evaluated by the vibrio fischeri and ECOSAR model, respectively. Many primary by-products were proven to be more toxic than the parent chemicals, raising the wider issue of extended potency for these compounds with regards to their ecotoxicity. These results have implications for assessing the degradative fate and risk of these chemicals during the AOPs.
Recent advances in drug development and bioactive molecules that covalently target lysine residues have shown substantial progress. Both reversible and irreversible covalent inhibitors are developed for targeting lysine residues. The identification of protein targets and binding sites of these lysine-targeting molecules in the whole proteome is crucial to understand their proteome-wide selectivity. For covalent inhibitors, the pull down-based methods including activity-based protein profiling (ABPP) are commonly used to profile their target proteins. For covalent reversible inhibitors, it is not easy to pull down the potential protein targets as the captured proteins may get off beads because of the reversible manner. Here, we report a pair of isotope-labelled click-free probes to competitively identify the protein targets of lysine-targeting covalent reversible small molecules. This pair of isotopic probes consists of a lysine-reactive warhead, a desthiobiotin moiety and isotopicable linker. This integrated probe could eliminate the background proteins induced by the click chemistry during the pull-down process. To demonstrate the feasibility of our newly-developed probes for the protein target identification, we selected the natural product Gossypol in that we proved for the first time that it could modify the lysine residue in a covalent reversible manner. Finally, we confirmed that this pair of integrated probes can be used in a competitive manner to precisely identify the protein target as well as binding sites of Gossypol. Interestingly, pretreatment of Gossypol could stop the antibody from recognizing Gossypol-binding proteins. Together, our isotope-labeled click-free probes could be used for whole-proteome profiling of lysine-targeting covalent reversible small molecules.
The selective conversion of CO2 and NH3 into valuable nitriles presents significant potential for CO2 utilization. In this study, we exploited the synergistic interplay between silicon and fluoride to augment the nickel-catalyzed reductive cyanation of aryl pseudohalides containing silyl groups, utilizing CO2 and NH3 as the CN source. Our methodology exhibited exceptional compatibility with diverse functional groups, such as alcohols, ketones, ethers, esters, nitriles, olefins, pyridines, and quinolines, among others, as demonstrated by the successful synthesis of 58 different nitriles. Notably, we achieved high yields in the preparation of bifunctionalized molecules, including intermediates for perampanel, derived from o-silylaryl triflates, which are well-known as aryne precursors. Remarkably, no degradation of substrates or formation of aryne intermediates were observed. Mechanistic studies imply that the formation of penta-coordinated silyl isocyanate intermediates is crucial for the key C–C coupling step and the presence of vicinal silyl group in the substrate is beneficial to further make this step kinetically favorable.
The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis, especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups. Thus, stereoselective synthesis of multi-substituted ten-membered rings is attractive. Herein, a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem [3 + 3] cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed. Products containing two or multiple stereocenters could be obtained in up to 96% yield with high regioselectivity and diastereoselectivity. Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans, bicyclo[4.4.0] or bicyclo[5.3.0] skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity. Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0] skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.
Algal copper uptake (i.e., Cu bioavailability) in the euphotic zone plays a vital role in algal photosynthesis and respiration, affecting the primary productivity and the source and sink of atmospheric carbon. Algal Cu uptake is controlled by natural dissolved organic Cu (DOCu) speciation (i.e., complexed with the dissolved organic matter) that conventionally could be tested by model prediction or molecular-level characterizations in the lab, while DOCu uptake are hardly directly assessed. Thus, the new chemistry-biology insight into the mechanisms of the Cu uptake process in algae is urgent. The DOCu speciation transformation (organic DOCu to free Cu(Ⅱ) ions), enzymatic reduction-induced valence change (reduction of free Cu(Ⅱ) to Cu(Ⅰ) ions), and algal Cu uptake at the algae-water interface are imitated. Herein, an intelligent system with DOCu colorimetric sensor is developed for real-time monitoring of newly generated Cu(Ⅰ) ions. Deep learning with whole sample image-based characterization and powerful feature extraction capabilities facilitates colorimetric measurement. In this context, the Cu bioavailability with 7 kinds of organic ligands (e.g., amino acids, organic acids, carbohydrates) can be predicted by the mimetic intelligent biosensor within 15.0 min, i.e., the DOCu uptake and speciation is successfully predicted and streamlined by the biomimetic approach.
Bridged bicyclic cores have been recognized as valuable bioisosteres of benzene ring, which are of great value in medicinal chemistry. However, the development of fluorinated bicyclic skeletons, which encompass two privileged elements widely acknowledged for fine tuning the working effect of target molecules, are far less common. Herein, we present a general and practical synthesis of gem–difluorobicyclo[2.1.1]hexanes (diF-BCHs) from readily available difluorinated hexa-1,5-dienes through energy transfer photocatalysis. By taking advantage of an efficient Cope rearrangement, the preparation of both constitutional isomers of diF-BCHs is readily achieved under identical conditions. The operational simplicity, mild conditions and wide scope further highlight the potential application of this protocol. Moreover, computational studies indicated a positive effect of fluorine atoms in lowering either the triplet or FMO energies of the hexa-1,5-diene substrates, thus promoting the present photoinduced [2 + 2] cycloaddition.
Combining cytotoxic drugs with tumor microenvironment (TME) modulator agents is an effective strategy to enhance anti-tumor effects. In this study, two natural anti-tumor active ingredients celastrol (CEL) and glycyrrhetinic acid (GA) were combined for tumor treatment. In order to ensure the precise co-delivery and controllable synchronous release of combined drugs to tumors, it is necessary to construct a suitable nano-drug delivery platform. Based on this, we coupled hyaluronic acid (HA) with CEL by amide reaction to obtain an amphiphilic polymer prodrug HA-SS-CEL, and GA was spontaneously loaded into polymer micelles by self-assembly to obtain G/HSSC-M. G/HSSC-M has ideal size distribution, redox-responsive synchronous drug release, enhanced tumor cell internalization and in vivo tumor targeting. Compared with free drugs, the construction of multifunctional polymer micelles makes G/HSSC-M show better anticancer effect at the same concentration, and can significantly inhibit the proliferation and migration of HepG2 and 4T1 cells. In the in vivo experiments, G/HSSC-M achieved a tumor inhibition rate as high as 75.12% in H22 tumor-bearing mice. The mechanism included regulation of M1/M2 macrophage polarization, inhibition of Janus kinase 1/signal transducer and activator of transcription 3 (JAK1/STAT3) signaling pathway, and remodeling of tumor blood vessels. Therefore, the development of prodrug micelles co-loaded with CEL and GA provides a promising drug co-delivery strategy for combined cancer therapy.
Self-assembled prodrug nanomedicine has emerged as an advanced platform for antitumor therapy, mainly comprise drug modules, response modules and modification modules. However, existing studies usually compare the differences between single types of modification modules, neglecting the impact of steric-hindrance effect caused by chemical structure. Herein, single-tailed modification module with low-steric-hindrance effect and two-tailed modification module with high-steric-hindrance effect were selected to construct paclitaxel prodrugs (P-LAC18 and P-BAC18), and the in-depth insights of the steric-hindrance effect on prodrug nanoassemblies were explored. Notably, the size stability of the two-tailed prodrugs was enhanced due to improved intermolecular interactions and steric hindrance. Single-tailed prodrug nanoassemblies were more susceptible to attack by redox agents, showing faster drug release and stronger antitumor efficacy, but with poorer safety. In contrast, two-tailed prodrug nanoassemblies exhibited significant advantages in terms of pharmacokinetics, tumor accumulation and safety due to the good size stability, thus ensuring equivalent antitumor efficacy at tolerance dose. These findings highlighted the critical role of steric-hindrance effect of the modification module in regulating the structure-activity relationship of prodrug nanoassemblies and proposed new perspectives into the precise design of self-assembled prodrugs for high-performance cancer therapeutics.
The chemo-, regio-, and enantio-controlled synthesis of P-chiral phosphines in a general and efficient manner remains a significant synthetic challenge. In this study, a Pd-catalyzed hydrofunctionalization is developed for the highly selective synthesis of P-stereogenic alkenylphosphinates and alkenylphosphine oxides via conjugate addition of enynes. Notably, this methodology is suitable for both phosphine oxide and phosphinate nucleophiles, providing a versatile approach for the construction of diverse P-chiral organophosphosphorus compound.
Traditional electrospray ionization tandem mass spectrometry (ESI-MSn) has been a powerful tool in diverse research areas, however, it faces great limitations in the study of protein-small molecule interactions. In this article, the state-of-the-art temperature-controlled electrospray ionization tandem mass spectrometry (TC-ESI-MSn) is applied to investigate interactions between ubiquitin and two flavonol molecules, respectively. The combination of collision-induced dissociation (CID) and MS solution-melting experiments facilitates the understanding of flavonol-protein interactions in a new dimension across varying temperature ranges. While structural changes of proteins disturbed by small molecules are unseen in ESI-MSn, TC-ESI-MSn allows a simultaneous assessment of the stability of the complex in both gas and liquid phases under various temperature conditions, meanwhile investigating the impact on the protein’s structure and tracking changes in thermodynamic data, and the characteristics of structural intermediates.
Neutrophil extracellular traps (NETs) formation (NETosis), is a crucial immune system mechanism mediated by neutrophils, measuring the capacity to induce NETosis is proposed as a clinical biomarker indicating the severity of COVID-19 and long COVID. Azvudine (FNC), has shown efficacy in treating SARS-CoV-2 infection and potential for alleviating inflammation. However, the molecular mechanism underlying its anti-inflammatory effects has not been extensively investigated. Therefore, a series of experiments were conducted on SARS-CoV-2 infected rhesus macaques (RMs) to investigate the anti-inflammatory effects of FNC. The experiments involved HE staining, mass spectrometry-based proteomics, validation experiments conducted in vivo using RMs tissues and in vitro differentiation of HL-60 cells. Additionally, interaction investigations were carried out utilizing LiP-MS, CETSA, Co-IP along with molecular docking. The results demonstrated that FNC treatment effectively alleviated neutrophil infiltration and attenuated inflammatory injury following infection. In addition to exhibiting antiviral effects, FNC treatment exhibited a reduction in inflammation-associated proteins and pathways such as myeloperoxidase (MPO) and the formation of NETs, respectively. Validation experiments confirmed the impact of FNC on regulating NETs formation, interaction experiments suggested that MPO may serves as a therapeutic target. The multifaceted properties of FNC, including its antiviral and anti-inflammatory characteristics, highlight the therapeutic potential in diseases associated with NETosis, particularly those involving concurrent SARS-CoV-2 infection, providing insights for drug development targeting MPO and NETosis-associated diseases.
Here we present a highly efficient protocol utilizing nickel-hydride hydrogen atom transfer catalysis for the regio- and enantioselective hydrofluorination of internal alkenes. This method efficiently assembles a wide array of enantioenriched β-fluoro amides with excellent regio- and enantioselectivity from internal unactivated alkenes. Mechanistic investigations suggest that this transformation proceeds via a NiH-hydrogen atom transfer to alkene, followed by a stereoselective fluorine atom transfer process. The weak coordination effect of the tethered amide group is identified as a crucial factor governing the observed regio- and enantioselectivity.
Nanoplastics exhibit greater environmental biotoxicity than microplastics and can be ingested by humans through major routes such as tap water, bottled water and other drinking water. Nanoplastics present a challenge for air flotation due to their minute particle size, negative surface potential, and similar density to water. This study employed dodecyltrimethylammonium chloride (DTAC) as a modifier to improve conventional air flotation, which significantly enhanced the removal of polystyrene nanoplastics (PSNPs). Conventional air flotation removed only 3.09% of PSNPs, while air flotation modified by dodecyltrimethylammonium chloride (DTAC-modified air flotation) increased the removal of PSNPs to 98.05%. The analysis of the DTAC-modified air flotation mechanism was conducted using a combination of instruments, including a zeta potential analyzer, contact angle meter, laser particle size meter, high definition camera, scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and Fourier transform infrared spectrometer (FTIR). The results indicated that the incorporation of DTAC reversed the electrostatic repulsion between bubbles and PSNPs to electrostatic attraction, significantly enhancing the hydrophobic force in the system. This, in turn, improved the collision adhesion effect between bubbles and PSNPs. The experimental results indicated that even when the flotation time was reduced to 7 min, the DTAC-modified air flotation still achieved a high removal rate of 96.26%. Furthermore, changes in aeration, pH, and ionic strength did not significantly affect the performance of the modified air flotation for the removal of PSNPs. The removal rate of PSNPs in all three water bodies exceeded 95%. The DTAC-modified air flotation has excellent resistance to interference from complex conditions and shows great potential for practical application.
Hyperglycemia resulting from diabetes mellitus (DM) exacerbates osteoporosis and fractures, damaging bone regeneration due to impaired healing capacity. Stem cell therapy offers the potential for bone repair, accelerating the healing of bone defects by introducing stem cells with osteogenic differentiation ability. Dental follicle stem cells (DFSCs) are a newly emerging type of dental stem cells that not only have the potential for multipotent differentiation but also hold easy accessibility and can stand long-term storage. However, DM-associated oxidative stress and inflammation elevate the risk of DFSCs dysfunction and apoptosis, diminishing stem cell therapy efficacy. Recent nanomaterial advances, particularly in DNA nanostructures like tetrahedral framework nucleic acids (tFNAs), have been promising candidates for modulating cellular behaviors. Accumulating experiments have shown that tFNAs' cell proliferation and migration-promoting ability and induce osteogenic differentiation of stem cells. Meanwhile, tFNAs can scavenge reactive oxygen species (ROS) and downregulate the secretion of inflammatory factors by inhibiting various inflammation-related signaling pathways. Here, we applied tFNAs to modify DFSCs and observed enhanced osteogenic differentiation alongside ROS scavenging and anti-inflammatory effects mediated by suppressing the ROS/mitogen-activated protein kinases (MAPKs)/nuclear factor kappa-B (NF-κB) signaling pathway. This intervention reduced stem cell apoptosis, bolstering stem cell therapy efficacy in DM. Our study establishes a simple yet potent tFNAs-DFSCs system, offering potential as a bone repair agent for future DM treatment.
The asymmetric addition of aromatic organometallic compounds to the carbonyl group (C-3) of isatins, catalyzed by transition metals, has emerged as a remarkably efficient method for the synthesis of chiral 3-hydroxyoxindoles. Here, an exceptionally enantioselective approach was developed for the first time to achieve a catalytic NHK reaction of isatins with aromatic halides (both aryl and heteroaryl). Utilizing chiral cobalt complexes as catalysts, and the presence of a diboron reagent B2nep2 as both a reducing agent and determinant in enantiocontrol, has resulted in the triumphantly achieved synthesis of enantioenriched products. Compared to reported strategies, this approach exhibits remarkable compatibility with substrates bearing sensitive functional groups, such as halides and borate esters, while also eliminating the need for organometallic reagents as required in previous strategies. Through experimental investigations, the presence of aryl-cobalt species during the addition process was confirmed, rather than in-situ generation of an arylboron reagent. Furthermore, the successful attainment of the R absolute configuration through aryl addition was demonstrated.
Humic acid (HA), as a represent of natural organic matter widely existing in water body, dose harm to water quality and human health; however, it was commonly treated as an environmental background substance while not targeted contaminant in advanced oxidation processes (AOPs). Herein, we investigated the removal of HA in the alkali-activated biochar (KBC)/peroxymonosulfate (PMS) system. The modification of the original biochar (BC) resulted in an increased adsorption capacity and catalytic activity due to the introduction of more micropores, mesopores, and oxygen-containing functional groups, particularly carbonyl groups. Mechanistic insights indicated that HA is primarily chemically adsorbed on the KBC surface, while singlet oxygen (1O2) produced by the PMS decomposition served as the major reactive species for the degradation of HA. An underlying synergistic adsorption and oxidation mechanism involving a local high concentration reaction region around the KBC interface was then proposed. This work not only provides a cost-effective solution for the elimination of HA but also advances our understanding of the nonradical oxidation at the biochar interface.
Nanobelts are a rapidly developing family of macrocycles with appealing features. However, their host-guest chemistry is currently limited to the recognition of fullerenes via π–π interactions. Herein, we report two heteroatom-bridged [8]cyclophenoxathiin nanobelts ([8]CP-Me and [8]CP) encapsulate corannulene (Cora) to form bowl-in-bowl supramolecular structures stabilized mainly through CH–π interactions in solid-state. The convex surface of corannulene is oriented towards the cavity due to geometry complementarity. The complex Cora⊂[8]CP exhibits a unique 2:2 capsule-like structure in crystal packing, in which corannulene adopts a concave-to-concave assembling fashion. This work enriches the molecular recognition of nanobelts and demonstrates that CH–π interactions can act as the main driving force for nanobelts host-guest complexes.
The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives. However, both the mechanistic activation mode and the substrate scopes of this type of radical difunctionalizations are still limited. We demonstrate herein a modular photoredox strategy for the difunctionalization of alkenes, employing arylsulfonyl acetate as the bifunctional reagent. This approach involves a radical addition/Smiles rearrangement cascade process, offering a robust alternative for the synthesis of valuable γ,γ-diaryl and γ-aryl esters. A complementary oxidative bifunctional reagents activation mode is identified to govern the radical cascade reactions, facilitating the simultaneous incorporation of aryl and carboxylate-bearing alkyl groups into the alkenes with excellent diastereoselectivity. Noteworthy features of this method include mild reaction conditions, organophotocatalysis, high atom- and step-economy, excellent functional group compatibility and great structural diversity.
The continuous mutation and rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to the ineffectiveness of many antiviral drugs targeting the original strain. To keep pace with the virus' evolutionary speed, there is a crucial need for the development of rapid, cost-effective, and efficient inhibitor screening methods. In this study, we created a novel approach based on fluorescence resonance energy transfer (FRET) technology for in vitro detection of inhibitors targeting the interaction between the SARS-CoV-2 spike protein RBD (s-RBD) and the virus receptor angiotensin-converting enzyme 2 (ACE2). Utilizing crystallographic insights into the s-RBD/ACE2 interaction, we modified ACE2 by fusing SNAP tag to its N-terminus (resulting in SA740) and Halo tag to s-RBD’s C-terminus (producing R525H and R541H), thereby ensuring the proximity (< 10 nm) of labeled FRET dyes. We found that relative to the R541H fusion protein, R525H exhibited higher FRET efficiency, which attributed to the shortened distance between FRET dyes due to the truncation of s-RBD. Utilizing the sensitive FRET effect between SA740 and R525H, we evaluated its efficacy in detecting inhibitors of SARS-CoV-2 entry in solution and live cells. Ultimately, this FRET-based detection method was demonstrated high sensitivity, rapidity, and simplicity in solution and held promise for high-throughput screening of SARS-CoV-2 inhibitors.
Perovskite oxides have been widely applied as an effective catalyst in heterogeneous catalysis. However, the rational design of active catalysts has been restricted by the lack of understanding of the electronic structure. The correlations between surface properties and bulk electronic structure have been ignored. Herein, a simple handler of LaFeO3 with diluted HNO3 was employed to tune the electronic structure and catalytic properties. Experimental analysis and theoretical calculations elucidate that acid etching could raise the Fe valence and enhance Fe–O covalency in the octahedral structure, thereby lessening charge transfer energy. Enhanced Fe–O covalency could lower oxygen vacancy formation energy and enhance oxygen mobility. In-situ DRIFTS results indicated the inherent adsorption capability of Toluene and CO molecules has been greatly improved owing to higher Fe–O covalency. As compared, the catalysts after acid etching exhibited higher catalytic activity, and the T90 had a great reduction of 45 and 58 ℃ for toluene and CO oxidation, respectively. A deeper understanding of electronic structure in perovskite oxides may inspire the design of high-performance catalysts.
As a renovator in the field of gene editing, CRISPR-Cas9 has demonstrated immense potential for advancing next-generation gene therapy owing to its simplicity and precision. However, this potential faces significant challenges primarily stemming from the difficulty in efficiently delivering large-sized genome editing system (including Cas9 protein and sgRNA) into targeted cells and spatiotemporally controlling their activity in vitro and in vivo. Therefore, the development of CRISPR/Cas9 nanovectors that integrate high loading capacity, efficient encapsulation and spatiotemporally-controlled release is highly desirable. Herein, we have engineered a near-infrared (NIR) light-activated upconversion-DNA nanocapsule for the remote control of CRISPR-Cas9 genome editing. The light-responsive upconversion-DNA nanocapsules consist of macroporous silica (mSiO2) coated upconversion nanoparticles (UCNPs) and photocleavable o-nitrobenzyl-phosphate-modified DNA shells. The UCNPs act as a "nanotransducers" to convert NIR light (980 nm) into local ultraviolet light, thereby facilitating the cleavage of photosensitive DNA nanocapsules and enabling on-demand release of CRISPR-Cas9 encapsuled in the macroporous silica. Furthermore, by formulating a sgRNA targeted to a tumor gene (polo-like kinase-1, PLK-1), the CRISPR-Cas9 loaded UCNP-DNA nanocapsules (crUCNP-DNA nanocapsules) have effectively suppressed the proliferation of tumor cells through NIR light-activated gene editing both in vitro and in vivo. Overall, this UCNP-DNA nanocapsule holds tremendous potential for CRISPR-Cas9 delivery and remote-controlled gene editing in deep tissues, as well as the treatment of diverse diseases.
Metal hydrides serve as crucial intermediates in many chemical processes, facilitating the utilization of hydrogen resources. Traditionally, three-centre metal hydrides have been viewed as less reactive due to their multi-stabilization effects. However, recent discoveries show the "three-centre four-electron" (3c-4e) bridging hydride bond exhibits significant activity in boryl transition metal systems. This research employs computational techniques to explore the factors that influence the formation of the 3c-4e bridging hydride, focusing on boryl 3d non-noble transition metals ranging from chromium (Cr) to nickel (Ni). By analyzing bond distances and bond orders, the study sheds light on the electronic and structural characteristics of the B-H-M bridging hydride. It reveals a clear link between the metal centre's redox properties and the emergence of bridging hydrides. Specifically, metal centres like Cr and Co, which have lower oxidation states and electronegativity, are more inclined to form active 3c-4e bridging hydrides. These insights, derived from computational analyses, offer valuable guidelines for the development of active 3c-4e bridging metal hydrides, thereby contributing to the advancement of new hydrogen transformation catalysts.
Singlet oxygen (1O2), as an electrophilic oxidant, is essential for the selective water decontamination of pollutants from water. Herein, we showcase a high-performing electrocatalytic filtration system composed of carbon nanotubes functionalized with CoFe alloy nanoparticles (CoFeCNT) to selectively facilitate the electrochemical activation of O2 to 1O2. Benefiting from the prominently featured bimetal active sites of CoFeCNT, nearly complete production of 1O2 is achieved by the electrocatalytic activation of O2. Additionally, the proposed system exhibits a consistent pollutant removal efficiency > 90% in a flow-through reactor over 48 h of continuous operation without a noticeable decline in performance, highlighting the dependable stability of the system for practical applications. The flow-through configuration demonstrates a striking 8-fold enhancement in tetracycline oxidation compared to a conventional batch reactor. This work provides a molecular level understanding of the oxygen reduction reaction, showing promising potential for the selective removal of emerging organic contaminants from water.
Developing a high-efficiency catalyst with both superior low-temperature activity and good N2 selectivity is still challenging for the NH3 selective catalytic reduction (SCR) of NOx from mobile sources. Herein, we demonstrate the improved low-temperature activity and N2 selectivity by regulating the redox and acidic properties of MnCe oxides supported on etched ZSM-5 supports. The etched ZSM-5 enables the highly dispersed state of MnCeOx species and strong interaction between Mn and Ce species, which promotes the reduction of CeO2, facilitates electron transfer from Mn to Ce, and generates more Mn4+ and Ce3+ species. The strong redox capacity contributes to forming the reactive nitrate species and -NH2 species from oxidative dehydrogenation of NH3. Moreover, the adsorbed NH3 and -NH2 species are the reactive intermediates that promote the formation of N2. This work demonstrates an effective strategy to enhance the low-temperature activity and N2 selectivity of SCR catalysts, contributing to the NOx control for the low-temperature exhaust gas during the cold-start of diesel vehicles.
The intrinsic clustering behavior and kinetically sluggish conversion process of lithium polysulfides seriously limit the electrochemical reversibility of sulfur redox reactions in lithium-sulfur (Li-S) batteries. Here, we introduce molybdenum pentachloride (MoCl5) into the electrolyte which could coordinate with lithium polysulfides and inhibit their intrinsic clustering behavior, subsequently serving as an improved mediator with the bi-functional catalytic effect for Li2S deposition and activation. Moreover, the coordination bonding and accelerated conversion reaction can also greatly suppress the dissolution and shuttling of polysulfides. Consequently, such polysulfide complexes enable the Li-S coin cell to exhibit good long-term cycling stability with a capacity decay of 0.078% per cycle after 400 cycles at 2 C, and excellent rate performance with a discharge capacity of 589 mAh/g at 4 C. An area capacity of 3.94 mAh/cm2 is also achieved with a high sulfur loading of 4.5 mg/cm2 at 0.2 C. Even at -20 ℃, the modified cell maintains standard discharge plateaus with low overpotential, delivering a high capacity of 741 mAh/g at 0.2 C after 80 cycles. The low-cost and convenient MoCl5 additive opens a new avenue for the effective regulation of polysulfides and significant enhancement in sulfur redox conversion.
An electronic circular dichroism (ECD)-based chiroptical sensing method has been developed for β- and γ-chiral primary amines via a C–H activation reaction. With the addition of Pd(OAc)2, the flexible remote chiral primary amine fragment in the bidentate ligand intermediate was fixed to form a cyclopalladium complex, producing an intense ECD response. The correlation between the sign of Cotton effects and the absolute configuration of substrates was proposed, together with theoretical verification using time-dependent density functional theory (TDDFT). Chiroptical sensing of an important drug raw material was performed to provide rapid and accurate information on the absolute optical purity. This work introduces an alternative perspective of C–H activation reaction as well as a feasible chiroptical sensing method of remote chiral amines.
Achieving artificial simulations of multi-step energy transfer processes and conversions in nature remains a challenge. In this study, we present a three-step sequential energy transfer process, which was constructed through host-guest interactions between a piperazine derivative (PPE-BPI) with aggregation-induced emission (AIE) and cucurbit[7]uril (CB[7]) in water to serve as ideal energy donors. To achieve multi-step sequential energy transfer, we employ three distinct fluorescent dyes Eosin B (EsB), Sulforhodamine 101 (SR101), and Cyanine 5 (Cy5) as energy acceptors. The PPE-PBI-2CB[7]+EsB+SR101+Cy5 system demonstrates a highly efficient three-step sequential energy transfer mechanism, starting with PPE-PBI-2CB[7] and transferring energy successively to EsB, SR101, and finally to Cy5, with remarkable energy transfer efficiencies. More interestingly, with the progressive transfer of energy in the multi-step energy transfer system, the generation efficiency of superoxide anion radical (O2•–) increased gradually, which can be used as photocatalysts for selectively photooxidation of N-phenyltetrahydroisoquinoline in an aqueous medium with a high yield of 86% after irradiation for 18 h. This study offers a valuable investigation into the simulation of multi-step energy transfer processes and transformations in the natural world, paving the way for further research in the field.
A sp2 carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(VI) removal. The morphology and structure of rBDATN-HCl were analyzed and identified by SEM, FTIR, XRD and solid-state 13C NMR. It is found that the active functional groups, such as hydroxyl and amide, were introduced into BDATN after radiation reduction and acidification. The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(VI) above 99% after 60 min of illumination with a solid-liquid ratio of 0.5 mg/mL, showing outstanding performance, which is attributed to the increase of dispersibility and adsorption sites of rBDATN-HCl. In comparison to the cBDATN-HCl synthesized with chemical reduction, rBDATN-HCl exhibits a better photoreduction performance for Cr(VI), demonstrating the advantages of radiation preparation of rBDATN-HCl. It is expected that more functionalized sp2 carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.
An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis. It is the first time that allene was introduced into transition metal and NHC synergetic catalysis, which demonstrated a versatile three-component reaction pattern, thus enabling two C-C bonds forged regioselectively in the reaction. The important reaction intermediates were successfully captured and characterized by HRMS analysis, and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.
Chirality, ubiquitous in living matter, plays vital roles in a series of physiological processes. The clarification of the multiple functions of chirality in bioapplications may provide innovative methodologies for engineering anti-tumor agents. Nevertheless, the related research has been rarely explored. In this study, the chiral supramolecular l/d-cysteine (Cys)-Zn2+-indocyanine green (ICG) nanoparticles were constructed through the coordination interaction between l/d-Cys and Zn2+, followed by the encapsulation of ICG. Experimental findings revealed that the d-Cys-Zn2+-ICG exhibited 17.31 times higher binding affinity toward phospholipid-composed liposomes compared to l-Cys-Zn2+-ICG. Furthermore, driven by chirality-specific interaction, a 2.07 folds greater cellular internalization of d-Cys-Zn2+-ICG than l-Cys-Zn2+-ICG was demonstrated. Additionally, the triple-level chirality-dependent photothermal, photodynamic and Zn2+ releasing anti-tumor effects of l/d Cys-Zn2+-ICG in vitro were verified. As a result, the d-formed nanoparticles achieved 1.93 times higher anti-tumor efficiency than the l-formed ones. The triple-level chirality-mediated anti-tumor effect highlighted in this study underscores the enormous potential of chirality in biomedicine and holds substantial significance in improving cancer therapeutic efficacy.
Ferroptosis in combination with immune therapy emerges as a promising approach for cancer therapy. Herein, dual-responsive metal-polyphenol coordinated nanomedicines were developed for pH/glutathione (GSH)-responsive synergistic ferroptosis and immunotherapy. Our innovative strategy involves the development of a manganese-polyphenol coordinated nanostructure, leveraging the biocompatibility of bovine serum albumin (BSA) as a template to encapsulate the anticancer drug sorafenib. The tumor microenvironment (pH/GSH) prompts the disassembly of MnO2 and epigallocatechin gallate (EGCG), thereby releases the anticancer payload. Concurrently, MnO2 acts to deplete intracellular GSH, which in turn suppresses glutathione peroxidase activity, leading to an accumulation of lipid peroxides with cell ferroptosis. Additionally, the release of Mn2+ ions bolster the cyclic guanosine monophosphlic acid (GMP)-adenosine monophosphlic acid (AMP) synthase-stimulator of interferon gene (cGAS-STING) pathway, which, in conjunction with the immunogenic cell death (ICD) effect induced by tumor cell apoptosis, significantly promotes dendritic cell (DC) maturation and enhances the presentation of tumor antigens. This successively ignites a robust innate and adaptive immune response. Both in vitro and in vivo experiments have demonstrated that the concurrent administration of ferroptosis-inducing and immune-stimulating therapies can significantly inhibit tumor growth.
Candida albicans is one of the most common pathogens causing invasive fungal infections, with a mortality rate of up to 20%–50%. Amphotericin B (AmB), a biopharmaceutics classification system (BCS) IV drug, significantly inhibits Candida albicans. AmB is primarily administered via oral and intravenous infusion, but severe infusion adverse effects, nephrotoxicity, and potential hepatotoxicity limit its clinical application. Deep eutectic solvents (DESs), with excellent solubilization ability and skin permeability, are attractive for transdermal delivery. Herein, we used DESs to deliver AmB for antifungal therapy transdermally. We first prepared and characterized DESs with different stoichiometric ratios of choline (Ch) and geranate (Ge). DESs increased the solubility of AmB by a thousand-fold. In vitro and in vivo, skin permeation studies indicated that DES1:2 (Ch and Ge in 1:2 ratio) had the most outstanding penetration and delivered fluorescence dye to the dermis layer. Then, DES1:2-AmB was prepared and in vitro antifungal tests demonstrated that DES1:2-AmB had superior antifungal effects compared to AmB and DES1:2. Furthermore, DES1:2-AmB was skin-irritating and biocompatible. In conclusion, DES-AmB provides a new and effective therapeutic solution for fungal infections.
Nanochannel technology based on ionic current rectification has emerged as a powerful tool for the detection of biomolecules owing to unique advantages. Nevertheless, existing nanochannel sensors mainly focus on the detection of targets in solution or inside the cells, moreover, they only have a single function, greatly limiting their application. Herein, we fabricated SuperDNA self-assembled conical nanochannel, which was clamped in the middle of self-made device for two functions: Online detecting living cells released TNF-α and studying intercellular communication. Polyethylene terephthalate (PET) membrane incubated tumor associated macrophages and tumor cells was rolled up and inserted into the left and right chamber of the device, respectively. Through monitoring the ion current change in the nanochannel, tumor associated macrophages released TNF-α could be in situ and noninvasive detected with a detection limit of 0.23 pg/mL. Furthermore, the secreted TNF-α induced epithelial-mesenchymal transformation of tumor cells in the right chamber was also studied. The presented strategy displayed outstanding performance and multi-function, providing a promising platform for in situ non-destructive detection of cell secretions and related intercellular communication analysis.
Room-temperature phosphorescence (RTP) materials exhibiting long emission lifetimes have gained increasing attention owing to their potential applications in encryption, anti-counterfeiting, and sensing. However, most polymers exhibit a short RTP lifetime (<1 s) because of their unstable triplet excitons. Herein, a new strategy of polymer chain stabilized phosphorescence (PCSP), which yields a new kind of RTP polymers with an ultralong lifetime and a sensitive oxygen response, has been reported. The rigid polymer chains of poly(methyl mathacrylate) (PMMA) immobilize the emitter molecules through multiple interactions between them, giving rise to efficient RTP. Meanwhile, the loosely-packed amorphous polymer chains allow oxygen to diffuse inside, endowing the doped polymers with oxygen sensitivity. Flexible and transparent polymer films exhibited an impressive ultralong RTP lifetime of 2.57 s at room temperature in vacuum, which was among the best performance of PMMA. Intriguingly, their RTP was rapidly quenched in the presence of oxygen. Furthermore, RTP microparticles with a diameter of 1.63 µm were synthesized using in situ dispersion polymerization technique. Finally, oxygen sensors for quick, visual, and quantitative oxygen detection were developed based on the RTP microparticles through phosphorescence lifetime and image analysis. With distinctive advantages such as an ultralong lifetime, oxygen sensitivity, ease of fabrication, and cost-effectiveness, PCSP opens a new avenue to sensitive materials for oxygen detection.
Transition metal cobalt exhibits strong activation capabilities for alkanes, however, the instability of Co sites leads to sintering and coke deposition, resulting in rapid deactivation. Hierarchical zeolites, with their diverse pore structures and high surface areas, are used to effectively anchor metals and enhance coke tolerance. Herein, a post-treatment method using an alkaline solution was employed to synthesize meso-microporous zeolite supports, which were subsequently loaded with Co species for propane dehydrogenation catalyst. The results indicate that the application of NaOH, an inorganic base, produces supports with a larger mesopore volume and more abundant hydroxyl nests compared to TPAOH, an organic base. UV–vis, Raman, and XPS analyses reveal that Co in the 0.5Co/SN-1–0.05 catalyst is mainly in the form of tetrahedral Co2+, which effectively activates CH bonds. In contrast, the 0.5Co/S-1 catalyst contains mainly Co3O4 species. Co2+ supported on hierarchical zeolites shows better propane conversion (58.6%) and propylene selectivity (>96%) compared to pure silica zeolites. Coke characterization indicates that hierarchical zeolites accumulate more coke, but it is mostly in the form of easily removable disordered carbon. The mesopores in the microporous zeolite support help disperse the active Co metal and facilitate coke removal during dehydrogenation, effectively preventing deactivation from sintering and coke coverage.
On-demand droplet manipulation plays a critical role in microfluidics, bio/chemical detection and micro-reactions. Acoustic droplet manipulation has emerged as a promising technique due to its non-contact nature, biocompatibility and precision, circumventing the complexities associated with other methods requiring surface or droplet pretreatment. Despite their promise, existing methods for acoustic droplet manipulation often involve complex hardware setups and difficulty for controlling individual droplet amidst multiple ones. Here we fabricate simple yet effective acoustic tweezers for in-surface and out-of-surface droplet manipulation. It is found that droplets can be transported on the superhydrophobic surfaces when the acoustic radiation force surpasses the friction force. Using a two-axis acoustic tweezer, droplets can be maneuvered along arbitrarily programmed paths on the surfaces. By introducing multiple labyrinthine structures on the superhydrophobic surface, individual droplet manipulation is realized by constraining the unselected droplets in the labyrinthine structures. In addition, a three-axis acoustic tweezer is developed for manipulating droplets in three-dimensional space. Potential applications of the acoustic tweezers for micro-reaction, bio-assay and chemical analysis are also demonstrated.
Generally, gaining fundamental insights into chain processes during the combustion of flame-retardant polymers relies on the qualitative and quantitative characterization of key chain carriers. However, polymer combustion processes based on conventional solid-fuel combustion strategies, due to the high coupling of pyrolysis, combustion, soot formation and oxidation, exhibit relatively high complexity and poor flame stability, and lead to a huge obstacle to the use of optical diagnostics. Herein, a spatial-confinement combustion strategy, which can produce a special staged flame with multi-jets secondary wave, is devised to provide a highly decoupled combustion environment. Glowing soot particles are therefore decoupled from main chemiluminescence region and confined to the flame tip to provide a well-controlled, optical-thin test environment for combustion diagnostic. Based on this strategy, a multi-nozzle-separation (MNS) burner is designed and fabricated, and the combustion processes associated with four model compounds, PVC, PS, PP/TBBA blends and PP/RP blends are investigated by spontaneous spectral diagnosis, and the chemiluminescence fingerprint of key diatomic/triatomic intermediates (such as OH, CH, C2, ClO, Br2, and PHO) are clearly observed. This encouraging result means that the strategy of spatial-confinement combustion we proposed shows promising prospect in many subjects associated with combustion chain regulation, such as efficient design of flame retardants.
Heterocyclic compounds play an important role in organic hole transport materials (HTMs) for perovskite solar cells (PSCs). Herein, a series of linear D-π-D HTMs (OCBz, S-CBz, SO2-CBz) with different dibenzo-heterocycles core (dibenzofuran, dibenzothiophene, dibenzothiophene sulfone) were designed and synthesized, and their applications in PSCs were investigated. The intrinsic properties (CV, UV–vis, hole mobility and conductivity) were systematically investigated, demonstrating that all three materials are suitable HTMs for planar n-i-p type PSCs. Benefiting from the excellent hole mobility and conductivity, good film forming ability, and outstanding charge extraction and transport capability of S-CBz, FAPbI3-based PSCs using S-CBz as HTM achieved a PCE of 25.0%, which is superior to that of Spiro-OMeTAD-based PSCs fabricated under the same conditions (23.9%). Furthermore, due to the interaction between S and Pb2+, S-CBz-based PSC devices exhibited improved stability. This work demonstrates that dibenzothiophene-based architectures are promising candidates for high-performance HTMs in perovskite solar cell architectures.
Crystalized CeO2 structures were typically considered potential photocatalysts due to their great capacity to alter the active sites’ size and ability to absorb light. However, the controllable fabrication of well-defined hierarchical structures of CeO2 with high reactive facets is significant and challenging. Herein, a series of CeO2 supports including hierarchical flower-like (F-CeO2), ball-like (B-CeO2), cube-like (CCeO2), and rod-like CeO2(R-CeO2) supports were prepared by hydrothermal method (B-CeO2, R-CeO2 and CCeO2) or ice-bath method (F-CeO2) respectively. V atoms were selected as the active atoms and loaded on these supports. Their structure-activity relationship in photo-assisted thermal propane dehydrogenation (PTPDH) was investigated systematically. The samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption-desorption isotherms, and Fourier transform infrared spectrum. Results show that R-CeO2 support exhibits the biggest surface area thus achieving the best dispersion of VOx species. UV–vis spectrum and photoluminescence spectrum indicate that V/F-CeO2 has the best light adsorption property and V/R-CeO2 has the best carrier migration capacity. The activity tests demonstrate that the V/R-CeO2 has the largest net growth rate and the V/F-CeO2 has the biggest relative growth ratio. Furthermore, the non-thermal effect was confirmed by the kinetic method, which lowers the propane reaction orders, selectively promoting the first C–H bond activation. The light radiation TPSR experiment confirmed this point. DFT calculations show a good linear relationship between the energy barrier and the exchanged electron number. It inspires the design of high-reactive facets for boosting the intrinsic activity of the C–H bond in photo-assisted thermal chemical processes.
To get large dissymmetric factor (glum) of organic circularly polarized luminescence (CPL) materials is still a great challenge. Although helical chirality and planar chirality are usual efficient access to enhancement of CPL, they are not combined together to boost CPL. Here, a new tetraphenylethylene (TPE) tetracycle acid helicate bearing both helical chirality and planar chirality was designed and synthesized. Uniquely, synergy of the helical chirality and planar chirality was used to boost CPL signals both in solution and in helical self-assemblies. In the presence of octadecylamine, the TPE helicate could form helical nanofibers that emitted strong CPL signals with an absolute glum value up to 0.237. Exceptionally, followed by addition of para-phenylenediamine, the glum value was successively increased to 0.387 due to formation of bigger helical nanofibers. Compared with that of TPE helicate itself, the CPL signal of the self-assemblies was not only magnified by 104-fold but also inversed, which was very rare result for CPL-active materials. Surprisingly, the interaction of TPE helicate with xylylenediamine even gave a gel, which was transformed into suspension by shaking. Unexpectedly, the suspension showed 40-fold stronger CPL signals than the gel with signal direction inversion each other. Using synergy of the helical chirality and planar chirality to significantly boost CPL intensity provides a new strategy in preparation of organic CPL materials having very large glum value.
Triphenylamine (TPA) is the most promising donor fragment for the construction of long-wavelength thermally activated delayed fluorescence (TADF) emitters owing to its suitable dihedral angle that could enhance radiative decay to compete with the serious non-radiative decay. However, the moderate electron-donating capacity of TPA seriously limits the selection of acceptor for constructing long-wavelength TADF emitters with narrow bandgaps. To address this issue, in this work, the peripheral benzene of TPA was replaced with 1,4-benzodioxane and anisole to obtain two new electron-donating units N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-N-phenyl-2,3-dihydrobenzo[b][1,4]dioxin-6-amine (TPADBO, −5.02 eV) and 4-methoxy-N-(4-methoxyphenyl)-N-phenylaniline (TPAMO, −5.00 eV), which possess much shallower highest occupied molecule orbital (HOMO) energy levels than the prototype TPA (−5.33 eV). Based on TPA and the modified TPA donor fragments, three TADF emitters were designed and synthesized, namely Py-TPA, Py-TPADBO and Py-TPAMO, with the same acceptor fragment 12-(2,6-diisopropylphenyl)pyrido[2′,3′:5,6]pyrazino[2,3-f][1,10]phenanthroline (Py). Among them, Py-TPAMO exhibits the highest photoluminescence quantum yield of 78.4% and the smallest singlet-triplet energy gap, which is because the introduction of anisole does not cause significant molecule deformation for the excited Py-TPAMO. And Py-TPAMO-based OLEDs successfully realize a maximum external quantum efficiency of 25.5% with the emission peak at 605 nm. This work provides a series of candidate of donor fragments for the development of efficient long-wavelength TADF emitters.
A series of “half-sandwich” bis(imino)pyridyl iron complexes with a substituted 8-(p-X-phenyl)naphthylamine (X = OMe, Me, CF3) was designed and synthesized by combining weak π-π interaction with steric and electronic tunings. The weak noncovalent π-π interaction as well as the steric and electronic effects of bis(imino)pyridyl iron complexes were identified by experimental analyses and calculations. The roles of weak π-π interaction, steric bulk, and electronic tuning on the ethylene polymerization performance of bis(imino)pyridyl iron catalysts were studied in detail. The combination of π-π interaction with steric and electronic tunings can access to thermally stable bis(imino)pyridyl iron at 130 ℃.
Metal ions trigger Fenton/Fenton-like reactions, generating highly toxic hydroxyl radicals (•OH) for chemodynamic therapy (CDT), which is crucial in inducing lethal oxidative DNA damage and subsequent cell apoptosis. However, tumor cells can counteract this damage through repair pathways, particularly MutT homolog 1 (MTH1) protein attenuation of oxidative DNA damage. Suppression of MTH1 can enhance CDT efficacy, therefore, orderly integrating Fenton/Fenton-like agents with an MTH1 inhibitor is expected to significantly augment CDT effectiveness. Carrier-free CuTH@CD, self-assembled through the supramolecular orchestration of γ-cyclodextrin (γ-CD) with Cu2+ and the MTH1 inhibitor TH588, effectively overcoming tumor resistance by greatly amplifying oxidative damage capability. Without additional carriers and mediated by multiple supramolecular regulatory effects, CuTH@CD enables high drug loading content, stability, and uniform size distribution. Upon internalization by tumor cells, CuTH@CD invalidates repair pathways through Cu2+-mediated glutathione (GSH) depletion and TH588-mediated MTH1 inhibition. Meanwhile, both generated Cu+ ions and existing ones within the nanoassembly initiate a Fenton-like reaction, leading to the accumulation of •OH. This strategy enhances CDT efficiency with minimal side effects, improving oxidative damage potency and advancing self-delivery nanoplatforms for developing effective chemodynamic tumor therapies.
Green synthesis of drugs is of paramount importance for current public health and a prerequisite to new drugs exploiting. Nowadays, novel strategies of disease diagnosis and therapies are in blooming development as remarkable advances have been achieved which are all highly depended on drug development. Under the current requirements to high production capacity and novel synthesis methods of drugs, green synthesis based on strategies with different ways of empowering, advanced catalysts and unique reaction equipment are attracting huge attention and of great challenging. Higher quality products and environmentally friendly synthesis conditions are becoming more and more important for manufacturing process which has new requirements for catalyst materials and synthesis processes. Polyoxometalates (POMs) are class of transition metals-oxygen clusters with precise molecular structures and superior physicochemical properties which have made longstanding and important applications upon research community of functional materials, catalysis and medicine. In this review, the recent advances of polyoxometalates based strategies for green synthesis of drugs are summarized including POMs based catalysts, alternative reaction equipment based novel synthesis protocols. The significance of POMs to pharmaceutical and industrial field is highlighted and the related perspective for future development are well discussed.
Two-dimensional (2D) transition metal sulfides (TMDs) are emerging and highly well received 2D materials, which are considered as an ideal 2D platform for studying various electronic properties and potential applications due to their chemical diversity. Converting 2D TMDs into one-dimensional (1D) TMDs nanotubes can not only retain some advantages of 2D nanosheets but also providing a unique direction to explore the novel properties of TMDs materials in the 1D limit. However, the controllable preparation of high-quality nanotubes remains a major challenge. It is very necessary to review the advanced development of one-dimensional transition metal dichalcogenide nanotubes from preparation to application. Here, we first summarize a series of bottom-up synthesis methods of 1D TMDs, such as template growth and metal catalyzed method. Then, top-down synthesis methods are summarized, which included self-curing and stacking of TMDs nanosheets. In addition, we discuss some key applications that utilize the properties of 1D-TMDs nanotubes in the areas of catalyst preparation, energy storage, and electronic devices. Last but not least, we prospect the preparation methods of high-quality 1D-TMDs nanotubes, which will lay a foundation for the synthesis of high-performance optoelectronic devices, catalysts, and energy storage components
Proton exchange membrane water electrolysis (PEMWE) is a favorable technology for producing high-purity hydrogen under high current density using intermittent renewable energy. The performance of PEMWE is largely determined by the oxygen evolution reaction (OER), a sluggish four-electron reaction with a high reaction barrier. Nowadays, iridium (Ir)-based catalysts are the catalysts of choice for OER due to their excellent activity and durability in acidic solution. However, its high price and unsatisfactory electrochemical performance severely restrict the PEMWE’s practical application. In this review, we initiate by introducing the current OER reaction mechanisms, namely adsorbate evolution mechanism and lattice oxygen mechanism, with degradation mechanisms discussed. Optimized strategies in the preparation of advanced Ir-based catalysts are further introduced, with merits and potential problems also discussed. The parameters that determine the performance of PEMWE are then introduced, with unsolved issues and related outlooks summarized in the end.
Solid-state electrolytes (SSEs), as the core component within the next generation of key energy storage technologies - solid-state lithium batteries (SSLBs) - are significantly leading the development of future energy storage systems. Among the numerous types of SSEs, inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12 (LLZO) crystallized with the cubic Ia3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity, wide electrochemical voltage window, high shear modulus, and excellent chemical stability with electrodes. However, no SSEs possess all the properties necessary for SSLBs, thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement. Hence, this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration, Li vacancy concentration, Li carrier concentration and mobility, Li occupancy at available sites, lattice constant, triangle bottleneck size, oxygen vacancy defects, and Li-O bonding interactions. Furthermore, the general illustration of structures and fundamental features being crucial to chemical stability is examined, including Li concentration, Li-site occupation behavior, and Li-O bonding interactions. Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures, revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions. We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors, thus assisting in promoting the rapid development of alternative green and sustainable technologies.
Lateral flow immunoassay (LFIA), a rapid detection technique noted for simplicity and economy, has showcased indispensable applicability in diverse domains such as disease screening, food safety, and environmental monitoring. Nevertheless, challenges still exist in detecting ultra-low concentration analytes due to the inherent sensitivity limitations of LFIA. Recently, significant advances have been achieved by integrating enzyme activity probes and transforming LFIA into a highly sensitive tool for rapidly detecting trace analyte concentrations. Specifically, modifying natural enzymes or engineered nanozymes allows them to function as immune probes, directly catalyzing the production of signal molecules or indirectly initiating enzyme activity. Therefore, the signal intensity and detection sensitivity of LFIA are markedly elevated. The present review undertakes a comprehensive examination of pertinent research literature, offering a systematic analysis of recently proposed enzyme-based signal amplification strategies. By way of comparative assessment, the merits and demerits of current approaches are delineated, along with the identification of research avenues that still need to be explored. It is anticipated that this critical overview will garner considerable attention within the biomedical and materials science communities, providing valuable direction and insight toward the advancement of high-performance LFIA technologies.
Designing advanced hydrogels with controlled mechanical properties, drug delivery manner and multifunctional properties will be beneficial for biomedical applications. However, the further development of hydrogel is limited due to its poor mechanical property and structural diversity. Hydrogels combined with polymeric micelles to obtain micelle-hydrogel composites have been designed for synergistic enhancement of each original properties. Incorporation polymeric micelles into hydrogel networks can not only enhance the mechanical property of hydrogel, but also expand the functionality of hydrogel. Recent advances in polymeric micelle-hydrogel composites are herein reviewed with a focus on three typical micelle incorporation methods. In this review, we will also highlight some emerging biomedical applications in developing micelle-hydrogel composite with multiple functionalities. In addition, further development and application prospects of the micelle-hydrogels composites have also been addressed.
Chemical modification of native peptides and proteins is a versatile strategy to facilitate late-stage diversification for functional studies. Among the proteogenic amino acids, lysine is extensively involved in post-translational modifications and the binding of ligands to target proteins, making its selective modification attractive. However, lysine’s high natural abundance and solvent accessibility, as well as its relatively low reactivity to cysteine, necessitate addressing chemoselectivity and regioselectivity for the Lys modification of native proteins. Although Lys chemoselective modification methods have been well developed, achieving site-selective modification of a specific Lys residue remains a great challenge. In this review, we discussed the challenges of Lys selective modification, presented recent examples of Lys chemoselective modification, and summarized the currently known methods and strategies for Lys site-selective modification. We also included an outlook on potential solutions for Lys site-selective labeling and its potential applications in chemical biology and drug development.
The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature, humidity and air cleanliness. It is promising for metal-organic frameworks (MOFs), the multifunctional environment remediation materials, to be applied in heritage environmental protection. The advantages of MOFs lie in their multifunction like adsorption, photocatalysis, sterilization, as well as the controllable structure and properties that could be flexibly adjusted as demands, helping the heritage against various environmental threats. Thereby, the applications and the corresponding mechanisms of MOFs in cultural heritage preservation were reviewed in this work, including harmful gas adsorption, surface waterproofing, particulate matters (PM) removal, anti-bacterial and humidity control of environment. Finally, the selection principles and precautions of MOFs in heritage preservation were discussed, aiming to provide a forward-looking direction for the selection and application of MOFs.
As a versatile and environmentally benign oxidant, hydrogen peroxide (H2O2) is highly desired in sanitation, disinfection, environmental remediation, and the chemical industry. Compared with the conventional anthraquinone process, the electrosynthesis of H2O2 through the two-electron oxygen reduction reaction (2e− ORR) is an efficient, competitive, and promising avenue. Electrocatalysts and devices are two core factors in 2e− ORR, but the design principles of catalysts for different pH conditions and the development trends of relevant synthesis devices remain unclear. To this end, this review adopts a multiscale perspective to summarize recent advancements in the design principles, catalytic mechanisms, and application prospects of 2e− ORR catalysts, with a particular focus on the influence of pH conditions, aiming at providing guidance for the selective design of advanced 2e− ORR catalysts for highly-efficient H2O2 production. Moreover, in response to diverse on-site application demands, we elaborate on the evolution of H2O2 electrosynthesis devices, from rotating ring-disk electrodes and H-type cells to diverse flow-type cells. We elaborate on their characteristics and shortcomings, which can be beneficial for their further upgrades and customized applications. These insights may inspire the rational design of innovative catalysts and devices with high performance and wide serviceability for large-scale implementations.
Developing efficient, non-toxic, and low-cost emitters is a key issue in promoting the applications of electrochemiluminescence (ECL). Among varied ECL emitters, polymeric emitters are attracting dramatically increasing interest due to tunable structure, large surface area, brilliant transfer capability, and sustainable raw materials. In this review, we present a general overview of recent advances in developing polymeric luminophores, including their structural and synthetic methodologies. Methods rooted in straightforward unique structural modulation have been comprehensively summarized, aiming at enhancing the efficiency of ECL along with the underlying kinetic mechanisms. Moreover, as several conjugated polymers were just discovered in recent years, promising prospects and perspectives have also been deliberated. The insight of this review may provide a new avenue for helping develop advanced conjugated polymer ECL emitters and decode ECL applications.
As a novel two-dimensional (2D) material, MXenes are anticipated to have a significant impact on future aqueous energy storage and conversion technologies owing to their unique intrinsic laminar structure and exceptional physicochemical properties. Nevertheless, the fabrication and utilization of functional MXene-based devices face formidable challenges due to their susceptibility to oxidative degradation in aqueous solutions. This review begins with an outline of various preparation techniques for MXenes and their implications for structure and surface chemistry. Subsequently, the controversial oxidation mechanisms are discussed, followed by a summary of currently employed oxidation characterization techniques. Additionally, the factors influencing MXene oxidation are then introduced, encompassing chemical composition (types of M, X elements, layer numbers, terminations, and defects) as well as environment (atmosphere, temperature, light, potential, solution pH, free water and O2 content). The review then shifts its focus to strategies aiming to prevent or delay MXene oxidation, thereby expanding the applicability of MXenes in complex environments. Finally, the challenges and prospects within this rapidly-growing research field are presented to promote further advancements of MXenes in aqueous storage systems.
Homogeneous C–H and C–X borylation via transition-metal-catalysis have undergone rapid development in the past decades and become one of the most practical methods for the synthesis of organoboron compounds. However, the catalysts employed in homogeneous catalysis are generally expensive, sensitive, and difficult to separate from the reaction mixture and reuse. With the rapid development of heterogeneous catalysis, heterogeneous C–H and C–X borylation have emerged as highly efficient and sustainable approaches towards the synthesis of organoboron compounds. This review aims to highlight the recent advances in the synthesis of organoboron compounds employing heterogeneous C–H and C–X borylation strategies. We endeavor to shed light on new perspectives and inspire further research and applications in this emerging area.
The enantioselective separation of racemate, particularly those containing C(sp3)-H bonds knowns for their high bond dissociation energies and significant polarity, presents a significant challenge in pharmaceutical synthesis. Recent advances have witnessed the fusion of photocatalysis with hydrogen atom transfer (HAT) methodologies, marking a notable trend in synthesis of chiral molecules. This technique uses the excitation of a catalyst to activate substrates, enabling the selective isomerization of chiral centers containing C(sp3) configurations. This process distinctively facilitates the direct activation of the C(sp3)-H bond in targeted reagents. This review systematically discusses the photocatalytic isomerization of various chiral molecule featuring C(sp3)-H centers, capable of undergoing deracemization through two primary HAT mechanisms: direct and indirect pathways. From the perspective of synthetic organic chemistry, this field has progressed towards the development of isomerization strategies for molecules that incorporate an activating group at the α-position adjacent to the C(sp3) chiral center. Moreover, it covers methodologies applicable to molecules characterized by specific C-C and C-S bond configurations. The integration of photocatalysis with HAT technology thus provides valuable strategies for the synthesis of enantiopure compounds with enhanced selectivity and efficiency.
Utilizing transporter-mediated drug delivery to achieve effective oral absorption emerges as a promising strategy. Researchers have been concentrated on discovering solutions to the issues of low solubility and poor permeability of insoluble drugs, whereas, current reports have revealed that drug transporter proteins are abundantly expressed in the mucosa of intestinal epithelial cells, and that their mediated drug absorption effectively improved the bioavailability of orally administered drugs. There are two main categories based on the transporter mechanism, which include the family of ATP-binding cassette (ABC) transporters with efflux effects that reduce drug bioavailability and the family of solute carriers (SLC) transporters with uptake effects that promote drug absorption, respectively. Thus, we review studies of intestinal transporter-mediated delivery of drugs to enhance oral absorption, including the types of intestinal transporters, distribution characteristics, and strategies for enhancing oral absorption using transporter-mediated drug delivery systems are summarized, with the aim of providing important theoretical references for the development of intestinal-targeted delivery system.
Carbon dots (CDs) are an emerging class of zero-dimensional carbon nano optical materials that are as promising candidates for various applications. Through the exploration of scientific researchers, the optical band gap of CDs has been continuously regulated and red-shifted from the initial blue-violet light to longer wavelengths. In recent years, CDs with near-infrared (NIR) absorption/emission have been gradually reported. Because NIR light has deeper penetration and lower scattering and is invisible to the human eye, it has great application prospects in the fields of biological imaging and treatment, information encryption, optical communications, etc. Although there are a few reviews on deep red to NIR CDs, they only focus on the single biomedical direction. There is still a lack of comprehensive reviews focusing on NIR (≥700 nm) absorption and luminescent CDs and their multifunctional applications. Based on our research group’s findings on NIR CDs, this review summarizes recent advancements in their preparation strategies and applications, points out the current shortcomings and challenges, and anticipates future development trajectories.
Polycyclic compounds are widely found in natural products and drug molecules with important biological activities, which attracted the attention of many chemists. Phosphine-catalyzed nucleophilic addition is one of the most powerful tools for the construction of various cyclic compounds with the advantages of atom economy, mild reaction conditions and simplicity of operation. Allenolates, Morita−Baylis−Hillman (MBH) alcohols and their derivatives (MBHADs), electron-deficient olefins and alkynes are very efficient substrates in phosphine mediated annulations, which formed many phosphonium species such as β-phosphonium enolates, β-phosphonium dienolates and vinyl phosphonium ylides as intermediates. This review describes the reactivities of these phosphonium zwitterions and summarizes the synthesis of polycycle compounds through phosphine-mediated intramolecular and intermolecular sequential annulations. Thus, a systematic summary of the research process based on the phosphine-mediated sequential annulations of allenolates, MBH alcohols and MBHADs, electron-deficient olefins and alkynes are presented in Chapters 2–6, respectively.