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2021 Volume 49 Issue 6
2021, 49(6): 849-857
doi: 10.19756/j.issn.0253-3820.211223
Abstract:
Chemiluminescence (CL) and electrochemiluminescence (ECL) assays are widely utilized in clinical diagnosis, drug analysis, food testing, environmental monitoring and other fields because of their superiorities of high sensitivity, rapid analysis and facile operation. In this review, the recent advances of CL and ECL assays of acute myocardial infarction biomarkers were emphatically summarized. The diagnostic value of cardiac troponin, myoglobin, heart type fatty acid-binding protein, creatine kinase MB, copeptin and myocardial specific microRNAs as biomarkers were compared. The fabrication and application advantages of these Cl and ECL biosensors were discussed. Furthermore, the further research orientations were also prospected.
Chemiluminescence (CL) and electrochemiluminescence (ECL) assays are widely utilized in clinical diagnosis, drug analysis, food testing, environmental monitoring and other fields because of their superiorities of high sensitivity, rapid analysis and facile operation. In this review, the recent advances of CL and ECL assays of acute myocardial infarction biomarkers were emphatically summarized. The diagnostic value of cardiac troponin, myoglobin, heart type fatty acid-binding protein, creatine kinase MB, copeptin and myocardial specific microRNAs as biomarkers were compared. The fabrication and application advantages of these Cl and ECL biosensors were discussed. Furthermore, the further research orientations were also prospected.
2021, 49(6): 858-866,906
doi: 10.19756/j.issn.0253-3820.211187
Abstract:
Microbes widely exist in nature and possess the ability to transform carbon compounds into energy through respiratory metabolism, which are important for element biogeochemical cycle, matters and energy conversion via redox reactions and electron transfer. Electrochemical and its integrated technologies are convenient in revealing the electron transfer mechanism at biotic-abiotic interface. Scanning electrochemical microscopy (SECM) is a scanning probe technology for visualizing the local redox activity of a surface with a high sensitivity and spatial resolution, and it enables in situ monitor microbial respiratory activity, electricity generation ability and micro-environmental factors of biofilms. On the basis of the composition and working principles, this review discussed the functional role of SECM for in situ revealing the electron transfer mechanism, summarized the researches in applications fields of microbial chips, bio-electrochemical systems and metal corrosion, and finally made a conclusion on the opportunities and challenges of the microbial electrochemistry in the future.
Microbes widely exist in nature and possess the ability to transform carbon compounds into energy through respiratory metabolism, which are important for element biogeochemical cycle, matters and energy conversion via redox reactions and electron transfer. Electrochemical and its integrated technologies are convenient in revealing the electron transfer mechanism at biotic-abiotic interface. Scanning electrochemical microscopy (SECM) is a scanning probe technology for visualizing the local redox activity of a surface with a high sensitivity and spatial resolution, and it enables in situ monitor microbial respiratory activity, electricity generation ability and micro-environmental factors of biofilms. On the basis of the composition and working principles, this review discussed the functional role of SECM for in situ revealing the electron transfer mechanism, summarized the researches in applications fields of microbial chips, bio-electrochemical systems and metal corrosion, and finally made a conclusion on the opportunities and challenges of the microbial electrochemistry in the future.
2021, 49(6): 867-880
doi: 10.19756/j.issn.0253-3820.211261
Abstract:
Since the invention of the Coulter counter in the 1850s, with the maturity of single-channel current recording technology and nano-micro processing technology, the analytical methods based on micro-nano channels has gradually developed into an emerging sensing platform due to its simplicity. The advantages of rapidity and label-free, as well as high sensitivity and versatility, have attracted widespread attention. In the past two decades, researches on the behaviors of ion transport in confined spaces and the development of sensing technologies based on regulating ion transport in solid-state nanopores have led to the rapid development in this scientific field. This article focuses on the recent progress on the studies about the new principles and new methods for electrochemical analysis based on ion transport in solid-state micro-nano pores. The review mainly covers two aspects: the principle of the basic behavior of ion transport and the analysis method based on regulating ion transport in confined space.
Since the invention of the Coulter counter in the 1850s, with the maturity of single-channel current recording technology and nano-micro processing technology, the analytical methods based on micro-nano channels has gradually developed into an emerging sensing platform due to its simplicity. The advantages of rapidity and label-free, as well as high sensitivity and versatility, have attracted widespread attention. In the past two decades, researches on the behaviors of ion transport in confined spaces and the development of sensing technologies based on regulating ion transport in solid-state nanopores have led to the rapid development in this scientific field. This article focuses on the recent progress on the studies about the new principles and new methods for electrochemical analysis based on ion transport in solid-state micro-nano pores. The review mainly covers two aspects: the principle of the basic behavior of ion transport and the analysis method based on regulating ion transport in confined space.
2021, 49(6): 881-892
doi: 10.19756/j.issn.0253-3820.210409
Abstract:
Actin is a kind of cytoskeletal protein, which exists in the form of filamentous or cross-linked bundle network in cells. It involves many key cell physiological processes, including cell division, deformation, movement and migration. Bottom up reconstruction of actin filament/network helps to explore a series of physiological activities of cells. In this review, the mechanism of actin polymerization, and the polymerization behavior of actins in solution environment and in artificial cells are summarized. The characteristics of actin polymerization in different environments are discussed. The future direction of actin self-assembly in the field of artificial cells is prospected.
Actin is a kind of cytoskeletal protein, which exists in the form of filamentous or cross-linked bundle network in cells. It involves many key cell physiological processes, including cell division, deformation, movement and migration. Bottom up reconstruction of actin filament/network helps to explore a series of physiological activities of cells. In this review, the mechanism of actin polymerization, and the polymerization behavior of actins in solution environment and in artificial cells are summarized. The characteristics of actin polymerization in different environments are discussed. The future direction of actin self-assembly in the field of artificial cells is prospected.
2021, 49(6): 893-906
doi: 10.19756/j.issn.0253-3820.211106
Abstract:
Circulating tumor DNA (ctDNA) is a kind of cell-free DNA (cfDNA) derived from tumor, which may carry the same carcinogenic mutations and genetic alterations as those of a primary tumor. Because ctDNA is expected to be a molecular biomarker for non-invasive monitoring of cancer, the development of ctDNA analysis methods can efficiently promote the development of liquid biopsy technology for cancer diagnosis, prognosis evaluation, efficacy monitoring and genetic/epigenetic abnormalities. In the past decades, traditional DNA detection techniques such as polymerase chain reaction (PCR) and next generation sequencing (NGS) were applied to clinical detection of ctDNA. Recently, biosensors have been gradually employed to analyze ctDNA in blood samples in cancer patients, which bring new tools for detection of ctDNA. In this review, the ctDNA analysis methods, especially the new progress of ctDNA biosensors in recent five years, have been summarized. The currently technical challenges of these methods in clinical practice have also been briefly discussed, which may provide useful information for developing new liquid biopsy methods of cancer.
Circulating tumor DNA (ctDNA) is a kind of cell-free DNA (cfDNA) derived from tumor, which may carry the same carcinogenic mutations and genetic alterations as those of a primary tumor. Because ctDNA is expected to be a molecular biomarker for non-invasive monitoring of cancer, the development of ctDNA analysis methods can efficiently promote the development of liquid biopsy technology for cancer diagnosis, prognosis evaluation, efficacy monitoring and genetic/epigenetic abnormalities. In the past decades, traditional DNA detection techniques such as polymerase chain reaction (PCR) and next generation sequencing (NGS) were applied to clinical detection of ctDNA. Recently, biosensors have been gradually employed to analyze ctDNA in blood samples in cancer patients, which bring new tools for detection of ctDNA. In this review, the ctDNA analysis methods, especially the new progress of ctDNA biosensors in recent five years, have been summarized. The currently technical challenges of these methods in clinical practice have also been briefly discussed, which may provide useful information for developing new liquid biopsy methods of cancer.
2021, 49(6): 907-921
doi: 10.19756/j.issn.0253-3820.211258
Abstract:
Nanozymes are nanomaterials with enzyme-like catalytic activities, which have attracted extensive attention due to their ability to solve some limitations of enzymes, such as poor stability, high cost and difficulty in mass production. Due to the advantages such as good biocompatibility, stability and ease of functionalization, carbon-based nanozymes have shown great application prospects. In this review, the recent progress of carbon-based nanozymes including carbon nanozymes, heteroatom-doped carbon nanozymes and metal-doped carbon nanozymes is introduced. Then, the catalytic mechanism of carbon-based nanozymes and their applications in biosensing are summarized in detail. Finally, current challenges and future perspectives for carbon-based nanozymes are discussed and outlooked.
Nanozymes are nanomaterials with enzyme-like catalytic activities, which have attracted extensive attention due to their ability to solve some limitations of enzymes, such as poor stability, high cost and difficulty in mass production. Due to the advantages such as good biocompatibility, stability and ease of functionalization, carbon-based nanozymes have shown great application prospects. In this review, the recent progress of carbon-based nanozymes including carbon nanozymes, heteroatom-doped carbon nanozymes and metal-doped carbon nanozymes is introduced. Then, the catalytic mechanism of carbon-based nanozymes and their applications in biosensing are summarized in detail. Finally, current challenges and future perspectives for carbon-based nanozymes are discussed and outlooked.
2021, 49(6): 922-930
doi: 10.19756/j.issn.0253-3820.211263
Abstract:
Electrochemical analysis with the inherent advantages such as fast response, high sensitivity and operational simplicity has been widely investigated and developed in various research and application fields. To obtain analysis results of high sensitivity, good selectivity and long-term stability, considerable efforts have been made to develop a variety of nanomaterials to construct the high-efficient sensing interface, thus realizing the improvement of analytic performance. Aerogels derived from the preformed colloidal nanoparticles are a new class of porous material. They feature merits of low density, large specific surface area, good mechanical deformation, hierarchical porous structure, and high catalytic properties, which extends the structural characteristics as well as physicochemical properties of nanoscale building blocks to macroscale. These characteristics make the aerogels as superior sensing materials with high sensitivity, excellent selectivity, and fast response in electrochemical analysis. This mini-review mainly highlights the recent progress of novel aerogel materials in electroanalytical sensing, and emphasizes their applications in human health and environmental monitoring. Finally, its development prospects are discussed.
Electrochemical analysis with the inherent advantages such as fast response, high sensitivity and operational simplicity has been widely investigated and developed in various research and application fields. To obtain analysis results of high sensitivity, good selectivity and long-term stability, considerable efforts have been made to develop a variety of nanomaterials to construct the high-efficient sensing interface, thus realizing the improvement of analytic performance. Aerogels derived from the preformed colloidal nanoparticles are a new class of porous material. They feature merits of low density, large specific surface area, good mechanical deformation, hierarchical porous structure, and high catalytic properties, which extends the structural characteristics as well as physicochemical properties of nanoscale building blocks to macroscale. These characteristics make the aerogels as superior sensing materials with high sensitivity, excellent selectivity, and fast response in electrochemical analysis. This mini-review mainly highlights the recent progress of novel aerogel materials in electroanalytical sensing, and emphasizes their applications in human health and environmental monitoring. Finally, its development prospects are discussed.
2021, 49(6): 931-940
doi: 10.19756/j.issn.0253-3820.211259
Abstract:
Gold nanoclusters have received great attention in the past years due to their excellent fluorescence properties, good biocompatibility, ultra-small size and good catalytic activity. Recently, the discovery and research on the enzyme-like activity of these gold nanoclusters have further expanded their application scope. In this review, we introduced the application of gold nanoclusters with enzyme-like catalytic activity in the field of colorimetric sensing, discussed the detection principles of different kinds of substances such as small biomolecules, ions, proteins and cancer cells by summarizing representative research works in this field. Finally, a prospect on the future development was given.
Gold nanoclusters have received great attention in the past years due to their excellent fluorescence properties, good biocompatibility, ultra-small size and good catalytic activity. Recently, the discovery and research on the enzyme-like activity of these gold nanoclusters have further expanded their application scope. In this review, we introduced the application of gold nanoclusters with enzyme-like catalytic activity in the field of colorimetric sensing, discussed the detection principles of different kinds of substances such as small biomolecules, ions, proteins and cancer cells by summarizing representative research works in this field. Finally, a prospect on the future development was given.
2021, 49(6): 941-951
doi: 10.19756/j.issn.0253-3820.211189
Abstract:
Mid-infrared photothermal (MIP) microscope is a far-field super-resolution infrared spectral and imaging technology, which improves the spatial resolution of infrared microscopic spectroscopy and imaging to 300-600 nm. Its appearance fills the gap between traditional far-field infrared microscope and near-field infrared microscope, provides a unique far-field optical solution for infrared microscopy to breaks the diffraction limit. In this review, the recent development of mid-infrared photothermal microscope was summarized, its principle, technical development and application were introduced, and finally the further developments was prospected.
Mid-infrared photothermal (MIP) microscope is a far-field super-resolution infrared spectral and imaging technology, which improves the spatial resolution of infrared microscopic spectroscopy and imaging to 300-600 nm. Its appearance fills the gap between traditional far-field infrared microscope and near-field infrared microscope, provides a unique far-field optical solution for infrared microscopy to breaks the diffraction limit. In this review, the recent development of mid-infrared photothermal microscope was summarized, its principle, technical development and application were introduced, and finally the further developments was prospected.
2021, 49(6): 952-962
doi: 10.19756/j.issn.0253-3820.210452
Abstract:
Electrochemical water splitting, a highly-efficient and environment-friendly technology has been considered as one of the most promising methods for hydrogen production. However, a large overpotential is generally required to achieve the current density for industrial water electrolysis. As a result, it is highly desirable to develop high-performance and cost-effective hydrogen evolution reaction (HER) electrocatalysts for the widespread application of water splitting. Perovskite oxides have emerged as a new category of nonprecious metal catalysts for electrocatalytic HER due to their low cost, abundant compositions and flexible structures. In this review, the HER mechanism in alkaline environment is briefly elaborated. Then, the research progress of perovskite oxides in HER is reviewed. Moreover, the strategies (ion doping, heterostructure engineering, morphology and structure regulation, etc.) for promoting HER performance are discussed and analyzed. Finally, the remaining challenges faced by perovskite HER electrocatalysts and the future prospects are put forward.
Electrochemical water splitting, a highly-efficient and environment-friendly technology has been considered as one of the most promising methods for hydrogen production. However, a large overpotential is generally required to achieve the current density for industrial water electrolysis. As a result, it is highly desirable to develop high-performance and cost-effective hydrogen evolution reaction (HER) electrocatalysts for the widespread application of water splitting. Perovskite oxides have emerged as a new category of nonprecious metal catalysts for electrocatalytic HER due to their low cost, abundant compositions and flexible structures. In this review, the HER mechanism in alkaline environment is briefly elaborated. Then, the research progress of perovskite oxides in HER is reviewed. Moreover, the strategies (ion doping, heterostructure engineering, morphology and structure regulation, etc.) for promoting HER performance are discussed and analyzed. Finally, the remaining challenges faced by perovskite HER electrocatalysts and the future prospects are put forward.
2021, 49(6): 963-972
doi: 10.19756/j.issn.0253-3820.201589
Abstract:
Tetracycline (TC) is an important antibiotic drug because of its excellent broad-spectrum sterilization effect in clinical medicine and animal husbandry. However, the abuse of antibiotics will result in antibiotic resistance and nephrotoxicity to mammals and seriously endanger ecosystems and human health. Consequently, it is significant to develop efficient, sensitive, and rapid detection methods towards TC. This review summarizes optical analytical methods towards TC detection based on nanomaterials, especially the research progress of fluorescence analysis. Finally, future trends of TC sensors are also discussed.
Tetracycline (TC) is an important antibiotic drug because of its excellent broad-spectrum sterilization effect in clinical medicine and animal husbandry. However, the abuse of antibiotics will result in antibiotic resistance and nephrotoxicity to mammals and seriously endanger ecosystems and human health. Consequently, it is significant to develop efficient, sensitive, and rapid detection methods towards TC. This review summarizes optical analytical methods towards TC detection based on nanomaterials, especially the research progress of fluorescence analysis. Finally, future trends of TC sensors are also discussed.
2021, 49(6): 973-981
doi: 10.19756/j.issn.0253-3820.201723
Abstract:
Rapid and sensitive detection of soluble interleukin-2 receptor (sIL-2R) in serum is believed to be of vital importance in clinical diagnosis. In this study, a colloidal gold-labeled immunochromatographic strip was developed for rapid and quantitative detection of sIL-2R in real sample. The goat anti-rabbit secondary antibody (2ndAb) and rabbit anti-mouse sIL-2R monoclonal antibody (cAb) were sprayed onto the nitrocellulose membrane as control line (C line) and test line (T line), respectively. The rabbit anti-mouse sIL-2R monoclonal antibody (dAb) modified gold nanoparticles were used as markers to fabricate the immunochromatographic strip for detection of sIL-2R by a sandwich method. Three gold nanoparticles with different sizes and morphologies were synthesized, and their effects on the detection performance of colloidal gold-labeled immunochromatographic strip were investigated. The experimental results showed that the detection performance of colloidal gold-labeled immunochromatographic strip for sIL-2R was closely related to the morphology and particle size of gold nanoparticles. Among them, gold nanorod (GNR)-based immunochromatographic strip had the widest linear range (1-6250 ng/mL) and the lowest detection limit (1.0 ng/mL). In addition, the concentrations of sIL-2R in the sera of triple-negative breast tumors (MDA-MB-231)-bearing BALB/c nude mice were successfully detected using GNR-based immunochromatographic strips, and it was found that the concentration of sIL-2R was positively correlated with tumor progression.
Rapid and sensitive detection of soluble interleukin-2 receptor (sIL-2R) in serum is believed to be of vital importance in clinical diagnosis. In this study, a colloidal gold-labeled immunochromatographic strip was developed for rapid and quantitative detection of sIL-2R in real sample. The goat anti-rabbit secondary antibody (2ndAb) and rabbit anti-mouse sIL-2R monoclonal antibody (cAb) were sprayed onto the nitrocellulose membrane as control line (C line) and test line (T line), respectively. The rabbit anti-mouse sIL-2R monoclonal antibody (dAb) modified gold nanoparticles were used as markers to fabricate the immunochromatographic strip for detection of sIL-2R by a sandwich method. Three gold nanoparticles with different sizes and morphologies were synthesized, and their effects on the detection performance of colloidal gold-labeled immunochromatographic strip were investigated. The experimental results showed that the detection performance of colloidal gold-labeled immunochromatographic strip for sIL-2R was closely related to the morphology and particle size of gold nanoparticles. Among them, gold nanorod (GNR)-based immunochromatographic strip had the widest linear range (1-6250 ng/mL) and the lowest detection limit (1.0 ng/mL). In addition, the concentrations of sIL-2R in the sera of triple-negative breast tumors (MDA-MB-231)-bearing BALB/c nude mice were successfully detected using GNR-based immunochromatographic strips, and it was found that the concentration of sIL-2R was positively correlated with tumor progression.
2021, 49(6): 982-991
doi: 10.19756/j.issn.0253-3820.211155
Abstract:
Au@Pt nanoparticles were grown in-situ on an amphiphilic polyvinyl alcohol aerogel (PAA) surface by a hydrothermal method to prepare an oxidase mimic (Au@Pt-PAAC) and was further applied to the visual detection of ascorbic acid. The abundant oxygen-containing functional groups on the PAA carrier provided nucleation sites for the growth of nanoparticles. Also, the core-shell structure of Au@Pt nanoparticles improved the oxidase-like activity of the material due to the synergistic effect and reduced the dosage of platinum, thus helping with cost control. Based on the oxidase-like activity of Au@Pt-PAAC material, a colorimetric sensor for the visual detection of ascorbic acid was constructed. Under the optimized experimental conditions, the linear range for the detection of ascorbic acid was 10-100 μmol/L, and the detection limit was 8.77 μmol/L. The sensor was also employed to evaluate the total antioxidant capacity of beverages and vitamin C tablets, with the experiments showing consistent results with the content of the ingredients in the sample instructions. The method established here is simple and visualized, with good anti-interference ability, and can be used to efficiently detect antioxidants.
Au@Pt nanoparticles were grown in-situ on an amphiphilic polyvinyl alcohol aerogel (PAA) surface by a hydrothermal method to prepare an oxidase mimic (Au@Pt-PAAC) and was further applied to the visual detection of ascorbic acid. The abundant oxygen-containing functional groups on the PAA carrier provided nucleation sites for the growth of nanoparticles. Also, the core-shell structure of Au@Pt nanoparticles improved the oxidase-like activity of the material due to the synergistic effect and reduced the dosage of platinum, thus helping with cost control. Based on the oxidase-like activity of Au@Pt-PAAC material, a colorimetric sensor for the visual detection of ascorbic acid was constructed. Under the optimized experimental conditions, the linear range for the detection of ascorbic acid was 10-100 μmol/L, and the detection limit was 8.77 μmol/L. The sensor was also employed to evaluate the total antioxidant capacity of beverages and vitamin C tablets, with the experiments showing consistent results with the content of the ingredients in the sample instructions. The method established here is simple and visualized, with good anti-interference ability, and can be used to efficiently detect antioxidants.
2021, 49(6): 992-998
doi: 10.19756/j.issn.0253-3820.210444
Abstract:
Due to the important biological activity and wide applications in biosensors and materials chemistry, i-motif structure switching and recognition have attracted more and more attention. In addition, intramolecular i-motif multimers have multiple repeating structural units, which are different from the surrounding environment of i-motif monomers. Although recognition of i-motif monomers by probes has been reported, the selective recognition of i-motif multimers over monomers has yet to be explored. In this work, it is found that hypericin (Hyp) can selectively distinguish human telomeric i-motif dimer from its monomer. The binding of the i-motif dimer depolymerizes the Hyp aggregation and causes a turn-on fluorescence response. However, the Hyp binding has no effect on the stability and conformation of the dimer structure. Since Hyp has a hydrogen bond pattern that is completely complementary to two thymines, the linker length experiment indicates that the in-between space of the two i-motif structural units in the dimer may be the binding site of Hyp via the hydrogen bonding with thymines from the loops. This binding space can effectively bind Hyp only when the i-motif dimer structure is formed under acidic conditions. This work demonstrates that Hyp as a fluorescent probe will play an important role in recognizing i-motif multimers.
Due to the important biological activity and wide applications in biosensors and materials chemistry, i-motif structure switching and recognition have attracted more and more attention. In addition, intramolecular i-motif multimers have multiple repeating structural units, which are different from the surrounding environment of i-motif monomers. Although recognition of i-motif monomers by probes has been reported, the selective recognition of i-motif multimers over monomers has yet to be explored. In this work, it is found that hypericin (Hyp) can selectively distinguish human telomeric i-motif dimer from its monomer. The binding of the i-motif dimer depolymerizes the Hyp aggregation and causes a turn-on fluorescence response. However, the Hyp binding has no effect on the stability and conformation of the dimer structure. Since Hyp has a hydrogen bond pattern that is completely complementary to two thymines, the linker length experiment indicates that the in-between space of the two i-motif structural units in the dimer may be the binding site of Hyp via the hydrogen bonding with thymines from the loops. This binding space can effectively bind Hyp only when the i-motif dimer structure is formed under acidic conditions. This work demonstrates that Hyp as a fluorescent probe will play an important role in recognizing i-motif multimers.
2021, 49(6): 999-1007
doi: 10.19756/j.issn.0253-3820.211129
Abstract:
Due to the excellent drug loading capacity, the amphiphobic dendritic macromolecule polyamide amine (PAMAM) has become an important drug carrier in nanodrug transport system. Therefore, real-time measurement of the cytotoxicity of different generations and different terminal groups of PAMAM in the near physiological environment is particularly important for drug carrier screening. In this study, taking the advantages of atomic force microscopy (AFM)-based nanoindentation technology for measuring the mechanical properties of individual cells under physiological conditions, the cell mechanical properties (Young's modulus) were compared after coincubation with different generations and different terminal groups of PAMAM at different concentrations for different tme, and the cytotoxicity of PAMAM was analyzed. Because there was no obvious charge effect, the change of Young's modulus of HeLa cells coincubated with G2-PAMAM-NH2 and G5-PAMAM-OH at different concentrations for different time was not obvious. The Young's modulus of HeLa cells was 0.61, 0.45, 0.46 and 0.22 kPa after coincubation with 0.5 μmol/L G5-PAMAM-NH2 for 0 h, 0.5 h, 1 h and 2 h, respectively. The Young's modulus of HeLa cells were 0.30, 0.20, 0.17 and 0.22 kPa after coincubation with G5-PAMAM-NH2 for 2 h at 0.5, 1.0, 2.0 and 5.0 μmol/L, respectively. It was found that the coincubation time was the dominant factor of cytotoxicity, while the cytotoxicity of G5-PAMAM-COOH was concentration-dependent. This study would lay a theoretical foundation for the better application of PAMAM in nanomedicine as a nanodrug carrier.
Due to the excellent drug loading capacity, the amphiphobic dendritic macromolecule polyamide amine (PAMAM) has become an important drug carrier in nanodrug transport system. Therefore, real-time measurement of the cytotoxicity of different generations and different terminal groups of PAMAM in the near physiological environment is particularly important for drug carrier screening. In this study, taking the advantages of atomic force microscopy (AFM)-based nanoindentation technology for measuring the mechanical properties of individual cells under physiological conditions, the cell mechanical properties (Young's modulus) were compared after coincubation with different generations and different terminal groups of PAMAM at different concentrations for different tme, and the cytotoxicity of PAMAM was analyzed. Because there was no obvious charge effect, the change of Young's modulus of HeLa cells coincubated with G2-PAMAM-NH2 and G5-PAMAM-OH at different concentrations for different time was not obvious. The Young's modulus of HeLa cells was 0.61, 0.45, 0.46 and 0.22 kPa after coincubation with 0.5 μmol/L G5-PAMAM-NH2 for 0 h, 0.5 h, 1 h and 2 h, respectively. The Young's modulus of HeLa cells were 0.30, 0.20, 0.17 and 0.22 kPa after coincubation with G5-PAMAM-NH2 for 2 h at 0.5, 1.0, 2.0 and 5.0 μmol/L, respectively. It was found that the coincubation time was the dominant factor of cytotoxicity, while the cytotoxicity of G5-PAMAM-COOH was concentration-dependent. This study would lay a theoretical foundation for the better application of PAMAM in nanomedicine as a nanodrug carrier.
2021, 49(6): 1008-1014
doi: 10.19756/j.issn.0253-3820.211091
Abstract:
Ni and NiMoO4 nanorods doped polyvinyl alcohol (PVA) carbon nanofibers (CNF) were prepared by electrospinning technique. The two carbon nanofibers were used as precursors and carbonized at high temperature respectively to prepare Ni-CNF and Ni-Mo2C-CNF composite materials. The composition and morphology of the prepared materials were characterized, and the direct electrocatalytic performance of the materials for glucose was investigated. The results showed that both Ni-CNF and Ni-Mo2C-CNF showed good electrocatalytic performance for glucose. The non-enzymatic glucose sensor based on Ni-Mo2C-CNF had low response potential (0.45 V), high sensitivity (198 μA·mmol/(L·cm2)), wide linear range (0.01-7.0 mmol/L), and low detection limit (4.3 μmol/L). Meanwhile, the non-enzymatic glucose sensor had good stability, reproducibility and selectivity. This study provided important practical reference value for the study of non-enzymatic glucose sensor.
Ni and NiMoO4 nanorods doped polyvinyl alcohol (PVA) carbon nanofibers (CNF) were prepared by electrospinning technique. The two carbon nanofibers were used as precursors and carbonized at high temperature respectively to prepare Ni-CNF and Ni-Mo2C-CNF composite materials. The composition and morphology of the prepared materials were characterized, and the direct electrocatalytic performance of the materials for glucose was investigated. The results showed that both Ni-CNF and Ni-Mo2C-CNF showed good electrocatalytic performance for glucose. The non-enzymatic glucose sensor based on Ni-Mo2C-CNF had low response potential (0.45 V), high sensitivity (198 μA·mmol/(L·cm2)), wide linear range (0.01-7.0 mmol/L), and low detection limit (4.3 μmol/L). Meanwhile, the non-enzymatic glucose sensor had good stability, reproducibility and selectivity. This study provided important practical reference value for the study of non-enzymatic glucose sensor.
2021, 49(6): 1015-1024
doi: 10.19756/j.issn.0253-3820.210424
Abstract:
Thermally activated delayed fluorescent (TADF) emitter is becoming one promising candidate as efficient electrochemiluminescence (ECL) chromophore. Compared to other types of purely organic ECL emitter, TADF emitters possess efficient triplet-to-singlet up-conversion capability via thermal activation, which can be more efficient for ECL emission since the dominant triplets (-75% in total under electrochemical excitation) can be harvested in this case. Previously, restricted by electrochemical stability of TADF emitters, various typical ECL modes, especially for reductive-oxidation co-reactant ECL mode, were not fully realized for TADF-type ECL system. In this work, one backbone-donor/pendant-acceptor type TADF conjugated polymer (named as PFSOTT5) was used to evaluate its potential in ECL topic. Impressively, such polymer displayed good electrochemical behaviors, which rendered the successful realization of all typical ECL mode including annihilation ECL, oxidative-reduction co-reactant ECL, reductive-oxidation co-reactant ECL with good stability. Systematic photophysics, electrochemical and ECL characterization and discussion were performed for PFSOTT5 in this work. Especially, for reductive-oxidation ECL using BPO as co-reactant, PFSOTT5-based ECL displayed stable and efficient ECL emission. The ECL efficiency of PFSOTT5-based ECL was even 5.79 times as compared to the typical fluorescent polymer counterpart. Accordingly, it is anticipated that such TADF polymer ECL has the application potentials in different ECL modes.
Thermally activated delayed fluorescent (TADF) emitter is becoming one promising candidate as efficient electrochemiluminescence (ECL) chromophore. Compared to other types of purely organic ECL emitter, TADF emitters possess efficient triplet-to-singlet up-conversion capability via thermal activation, which can be more efficient for ECL emission since the dominant triplets (-75% in total under electrochemical excitation) can be harvested in this case. Previously, restricted by electrochemical stability of TADF emitters, various typical ECL modes, especially for reductive-oxidation co-reactant ECL mode, were not fully realized for TADF-type ECL system. In this work, one backbone-donor/pendant-acceptor type TADF conjugated polymer (named as PFSOTT5) was used to evaluate its potential in ECL topic. Impressively, such polymer displayed good electrochemical behaviors, which rendered the successful realization of all typical ECL mode including annihilation ECL, oxidative-reduction co-reactant ECL, reductive-oxidation co-reactant ECL with good stability. Systematic photophysics, electrochemical and ECL characterization and discussion were performed for PFSOTT5 in this work. Especially, for reductive-oxidation ECL using BPO as co-reactant, PFSOTT5-based ECL displayed stable and efficient ECL emission. The ECL efficiency of PFSOTT5-based ECL was even 5.79 times as compared to the typical fluorescent polymer counterpart. Accordingly, it is anticipated that such TADF polymer ECL has the application potentials in different ECL modes.
2021, 49(6): 1025-1034
doi: 10.19756/j.issn.0253-3820.211053
Abstract:
A novel kinetically competitive aptasensor for detection of ricin toxin A chain (RTA) was fabricated based on the catalytic hairpin assembly (CHA) for signal amplification and transduction. The elements of kinetic competition contain aptamers (RA80), hairpin probes (HP1) and blockers, wherein the blockers kinetically compete with RA80 and HP1, but pre-binding of the target to its aptamer alters this kinetic competition and leads to more blocker binding to HP1. Then, more blockers binding to HP1 were separated as the catalyst for CHA reaction and increased fluorescence intensity. Thus, an indirect correlation between the fluorescence intensity and RTA concentration was constructed. Besides, the mismatched base pair introduced in the CHA circuit impeded uncatalyzed strand exchange reactions due to breathing or the mis-folding of nucleic acids into alternative conformers, which resulted in the decline of background signal and the improvement of signal-to-noise ratio. The limit of detection (LOD) for RTA was 0.88 nmol/L, which was comparable or even superior to other RTA determination strategies. The recoveries ranging from 91.2% to 107.9% were also satisfactory for RTA analysis in food powder. The proposed approach expanded the aptamer recognition mechanism and overcame the difficulty of the traditional antisense displacement strategy, bringing a bright hope to design and screen blockers for RNA aptamer with long sequence and complicated secondary structure without necessity of aptamer modification and requirement of lengthy pre-equilibration.
A novel kinetically competitive aptasensor for detection of ricin toxin A chain (RTA) was fabricated based on the catalytic hairpin assembly (CHA) for signal amplification and transduction. The elements of kinetic competition contain aptamers (RA80), hairpin probes (HP1) and blockers, wherein the blockers kinetically compete with RA80 and HP1, but pre-binding of the target to its aptamer alters this kinetic competition and leads to more blocker binding to HP1. Then, more blockers binding to HP1 were separated as the catalyst for CHA reaction and increased fluorescence intensity. Thus, an indirect correlation between the fluorescence intensity and RTA concentration was constructed. Besides, the mismatched base pair introduced in the CHA circuit impeded uncatalyzed strand exchange reactions due to breathing or the mis-folding of nucleic acids into alternative conformers, which resulted in the decline of background signal and the improvement of signal-to-noise ratio. The limit of detection (LOD) for RTA was 0.88 nmol/L, which was comparable or even superior to other RTA determination strategies. The recoveries ranging from 91.2% to 107.9% were also satisfactory for RTA analysis in food powder. The proposed approach expanded the aptamer recognition mechanism and overcame the difficulty of the traditional antisense displacement strategy, bringing a bright hope to design and screen blockers for RNA aptamer with long sequence and complicated secondary structure without necessity of aptamer modification and requirement of lengthy pre-equilibration.
2021, 49(6): 1035-1043
doi: 10.19756/j.issn.0253-3820.211034
Abstract:
Platinum nanoparticles were loaded onto the surface of poly(ethylene glycol)-modified graphene oxide (GO/PEG/Pt) via an in-situ reduction method. GO/PEG/Pt nanohybrids had excellent peroxidase-like activity in aqueous solution, and could catalyze H2O2 to produce ·OH rapidly, thus making the chromogenic substrate 3,3',5,5'-tetramethylbenzidine hydrochloride (TMB·2HCl) changed obviously and an absorption peak appeared at 652 nm in UV-Vis absorption spectrum. However, when the mercury ions (Hg2+) were introduced, Hg2+ was reduced to Hg0 by Pt0 and deposited on the surface of platinum nanoparticles to form platinum amalgam, which resulted in the occupation of surface-active sites of GO/PEG/Pt, the signal output of the system was inhibited, and the degree of inhibition varied linearly with Hg2+ concentration. Therefore, under the optimized experimental conditions, the visual colorimetric sensor was constructed to realize the sensitive analysis and real-time detection of Hg2+. The detection limit of spectral analysis was 3.96 nmol/L, and the detection limit of naked eye was 10 nmol/L. The method was applied to determination of Hg2+ in tap water and lake water, and the recoveries were between 95.5% and 108.6%.
Platinum nanoparticles were loaded onto the surface of poly(ethylene glycol)-modified graphene oxide (GO/PEG/Pt) via an in-situ reduction method. GO/PEG/Pt nanohybrids had excellent peroxidase-like activity in aqueous solution, and could catalyze H2O2 to produce ·OH rapidly, thus making the chromogenic substrate 3,3',5,5'-tetramethylbenzidine hydrochloride (TMB·2HCl) changed obviously and an absorption peak appeared at 652 nm in UV-Vis absorption spectrum. However, when the mercury ions (Hg2+) were introduced, Hg2+ was reduced to Hg0 by Pt0 and deposited on the surface of platinum nanoparticles to form platinum amalgam, which resulted in the occupation of surface-active sites of GO/PEG/Pt, the signal output of the system was inhibited, and the degree of inhibition varied linearly with Hg2+ concentration. Therefore, under the optimized experimental conditions, the visual colorimetric sensor was constructed to realize the sensitive analysis and real-time detection of Hg2+. The detection limit of spectral analysis was 3.96 nmol/L, and the detection limit of naked eye was 10 nmol/L. The method was applied to determination of Hg2+ in tap water and lake water, and the recoveries were between 95.5% and 108.6%.
2021, 49(6): 1044-1052
doi: 10.19756/j.issn.0253-3820.211221
Abstract:
Permanganate index (CODMn) is one of the important indicators in evaluating the pollution level of ground water. In this study, KMnO4 was used to treat water samples and the residual KMnO4 in water samples was treated by KI. On the basis of this, a simple, fast and low consumption method for determination of CODMn was established by way of chromogenic reaction. Under the optimum experiment conditions such as reaction temperature at 105 ℃, digestion for 20 min, 0.0040 mol/L KMnO4, and H2SO4 solution (1∶4, V/V), there was a good linear relationship between the absorbance of I3- solution and the concentration of CODMn. The detection limit ranged from 0.5 to 9.0 mg/L and the limit of detection was 0.2 mg/L. In the real water samples test, the adding standard recovery ranged from 100.0% to 108.0%. Compared with the national standard method, this method expanded the range of detection, simplified the reaction process, and admitted batch measurement. This method confirmed a good reproducibility, and was suitable for developing online monitoring method.
Permanganate index (CODMn) is one of the important indicators in evaluating the pollution level of ground water. In this study, KMnO4 was used to treat water samples and the residual KMnO4 in water samples was treated by KI. On the basis of this, a simple, fast and low consumption method for determination of CODMn was established by way of chromogenic reaction. Under the optimum experiment conditions such as reaction temperature at 105 ℃, digestion for 20 min, 0.0040 mol/L KMnO4, and H2SO4 solution (1∶4, V/V), there was a good linear relationship between the absorbance of I3- solution and the concentration of CODMn. The detection limit ranged from 0.5 to 9.0 mg/L and the limit of detection was 0.2 mg/L. In the real water samples test, the adding standard recovery ranged from 100.0% to 108.0%. Compared with the national standard method, this method expanded the range of detection, simplified the reaction process, and admitted batch measurement. This method confirmed a good reproducibility, and was suitable for developing online monitoring method.
2021, 49(6): 1053-1060
doi: 10.19756/j.issn.0253-3820.210418
Abstract:
A novel covalent organic framework (COFTFPB-TDF) was firstly synthesized by ammonaldehyde condensation reaction between 1,3,5-tris(p-formylphenyl) benzene and 1,4-benzenedicarbohydrazide. Then, three-dimensional macroporous carbon derived from kenaf stem (3D-KSC)/COFTFPB-TDF integrated electrode was obtained by growing COFTFPB-TDF on 3D-KSC. Scanning electron microscopy was used to characterize the structure of 3D-KSC/COFTFPB-TDF. The results showed that 3D-KSC/COFTFPB-TDF had lamellar structure and there were many holes to support other materials. The performance of 3D-KSC/COFTFPB-TDF electrode for detection of dopamine was studied by cyclic voltammetry. The results showed that the sensor had good performance for detecting dopamine, with low detection limit (0.045 μmol/L), wide linear range (0.134 μmol/L-0.06 mmol/L) and high sensitivity (369 μA/(mmol/L)/cm2). These excellent properties were mainly attributed to the larger specific surface area and pore structure of 3D-KSC/COFTFPB-TDF, which also made the material had a good application prospect in other aspects.
A novel covalent organic framework (COFTFPB-TDF) was firstly synthesized by ammonaldehyde condensation reaction between 1,3,5-tris(p-formylphenyl) benzene and 1,4-benzenedicarbohydrazide. Then, three-dimensional macroporous carbon derived from kenaf stem (3D-KSC)/COFTFPB-TDF integrated electrode was obtained by growing COFTFPB-TDF on 3D-KSC. Scanning electron microscopy was used to characterize the structure of 3D-KSC/COFTFPB-TDF. The results showed that 3D-KSC/COFTFPB-TDF had lamellar structure and there were many holes to support other materials. The performance of 3D-KSC/COFTFPB-TDF electrode for detection of dopamine was studied by cyclic voltammetry. The results showed that the sensor had good performance for detecting dopamine, with low detection limit (0.045 μmol/L), wide linear range (0.134 μmol/L-0.06 mmol/L) and high sensitivity (369 μA/(mmol/L)/cm2). These excellent properties were mainly attributed to the larger specific surface area and pore structure of 3D-KSC/COFTFPB-TDF, which also made the material had a good application prospect in other aspects.
