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2023 Volume 51 Issue 4
2023, 51(4): 463-471
doi: 10.19756/j.issn.0253-3820.221537
Abstract:
Metal-organic frameworks (MOFs) are a type of new crystalline porous material formed by self-assembly of metal ions/clusters and organic ligands. MOFs have shown huge potential in electrochemical sensing due to their high porosity, large specific surface area, high electrocatalytic activity, and adjustable and diverse structure. Among numerous MOFs, copper-based metal-organic frameworks (Cu-MOFs) have attracted more attention because of their high electrocatalytic activity. The studies on the properties and applications of Cu-MOFs prepared by different ligands and methods are increasing. Currently, Cu-MOFs are also achieving wide range of applications in life electrochemical sensing, environmental electrochemical detection and food safety electrochemical analysis. This article mainly introduced the recent research progress of Cu-MOFs prepared by different methods and their various composites combined with the relevant researches of our group in electrochemical sensing applications. Finally, the future applications and challenges of electrochemical sensors based on Cu-MOFs were prospected.
Metal-organic frameworks (MOFs) are a type of new crystalline porous material formed by self-assembly of metal ions/clusters and organic ligands. MOFs have shown huge potential in electrochemical sensing due to their high porosity, large specific surface area, high electrocatalytic activity, and adjustable and diverse structure. Among numerous MOFs, copper-based metal-organic frameworks (Cu-MOFs) have attracted more attention because of their high electrocatalytic activity. The studies on the properties and applications of Cu-MOFs prepared by different ligands and methods are increasing. Currently, Cu-MOFs are also achieving wide range of applications in life electrochemical sensing, environmental electrochemical detection and food safety electrochemical analysis. This article mainly introduced the recent research progress of Cu-MOFs prepared by different methods and their various composites combined with the relevant researches of our group in electrochemical sensing applications. Finally, the future applications and challenges of electrochemical sensors based on Cu-MOFs were prospected.
2023, 51(4): 472-483
doi: 10.19756/j.issn.0253-3820.221510
Abstract:
With the rapid development of traditional Chinese medicine (TCM) industry, the demand of TCM is increasing. The quality and safety of TCM are attracting more and more attention. Mycotoxin pollution, which not only affects the quality, and in serious cases, also may cause carcinogenic, teratogenic and mutagenic effects on human body, has become one of the key safety issues of TCM. Rapid and accurate detection of mycotoxins in TCM is essential to ensure the quality and safety. Optical biosensors have been widely applied to rapid detection of mycotoxins due to their advantages such as simplicity to operate, fast response, high sensitivity, and good accuracy. Notably, nanomaterials are extensively used in optical biosensors owing to their unique physicochemical and catalytic properties. This review summarized the optical biosensors for mycotoxins in recent years. The principles, application characteristics and construction methods progress of optical biosensors were emphasized. The optical biosensors were classified into fluorescence, colorimetry, chemiluminescence, surface enhanced Raman scattering and polarized light for detailed discussion. The effects of the main matrix components of TCM on optical biosensors were comprehensively discussed. The challenges and perspectives of optical biosensors for detection of mycotoxins in TCM were highlighted. It was aimed to provide guidance for sensitive, accurate and convenient supervision of the quality of Chinese medicinal materials.
With the rapid development of traditional Chinese medicine (TCM) industry, the demand of TCM is increasing. The quality and safety of TCM are attracting more and more attention. Mycotoxin pollution, which not only affects the quality, and in serious cases, also may cause carcinogenic, teratogenic and mutagenic effects on human body, has become one of the key safety issues of TCM. Rapid and accurate detection of mycotoxins in TCM is essential to ensure the quality and safety. Optical biosensors have been widely applied to rapid detection of mycotoxins due to their advantages such as simplicity to operate, fast response, high sensitivity, and good accuracy. Notably, nanomaterials are extensively used in optical biosensors owing to their unique physicochemical and catalytic properties. This review summarized the optical biosensors for mycotoxins in recent years. The principles, application characteristics and construction methods progress of optical biosensors were emphasized. The optical biosensors were classified into fluorescence, colorimetry, chemiluminescence, surface enhanced Raman scattering and polarized light for detailed discussion. The effects of the main matrix components of TCM on optical biosensors were comprehensively discussed. The challenges and perspectives of optical biosensors for detection of mycotoxins in TCM were highlighted. It was aimed to provide guidance for sensitive, accurate and convenient supervision of the quality of Chinese medicinal materials.
2023, 51(4): 484-491
doi: 10.19756/j.issn.0253-3820.211216
Abstract:
Mass spectrometry (MS) analysis has become one of the core technologies for clinical disease research. Traditional mass spectrometry techniques such as liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) often require multi-step pre-processing of different clinical samples, which can not meet the practical requirements of large samples and high throughput analysis in clinical settings, while these needs are driving the development of new technologies for mass spectrometry from laboratory to clinical applications. The lack of ideal preoperative diagnostic protocols for chest malignancies such as lung cancer and esophageal cancer, the long waiting time for intraoperative pathology to assess the nature of the cut edge, and the lack of ideal models to assess the risk of recurrence in the postoperative period are among the main reasons for ″under-treatment″ and ″over-treatment″ in clinical practice. This is one of the main reasons for ″under-treatment″ and ″over-treatment″ in clinical practice. Direct injection mass spectrometry has high specificity and sensitivity, which effectively improves the accuracy of sample nature determination and decreases the analysis time of samples in clinical analysis, providing important guidance for clinical diagnosis and chest tumor research. This review introduced the progress of the application of direct injection mass spectrometry in the perioperative diagnosis of thoracic tumors, and briefly described the prospects of the application of direct injection mass spectrometry combined with histological methods to explore thoracic tumor biomarkers for the prevention of postoperative recurrence.
Mass spectrometry (MS) analysis has become one of the core technologies for clinical disease research. Traditional mass spectrometry techniques such as liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) often require multi-step pre-processing of different clinical samples, which can not meet the practical requirements of large samples and high throughput analysis in clinical settings, while these needs are driving the development of new technologies for mass spectrometry from laboratory to clinical applications. The lack of ideal preoperative diagnostic protocols for chest malignancies such as lung cancer and esophageal cancer, the long waiting time for intraoperative pathology to assess the nature of the cut edge, and the lack of ideal models to assess the risk of recurrence in the postoperative period are among the main reasons for ″under-treatment″ and ″over-treatment″ in clinical practice. This is one of the main reasons for ″under-treatment″ and ″over-treatment″ in clinical practice. Direct injection mass spectrometry has high specificity and sensitivity, which effectively improves the accuracy of sample nature determination and decreases the analysis time of samples in clinical analysis, providing important guidance for clinical diagnosis and chest tumor research. This review introduced the progress of the application of direct injection mass spectrometry in the perioperative diagnosis of thoracic tumors, and briefly described the prospects of the application of direct injection mass spectrometry combined with histological methods to explore thoracic tumor biomarkers for the prevention of postoperative recurrence.
2023, 51(4): 492-501
doi: 10.19756/j.issn.0253-3820.221463
Abstract:
Phosphotyrosine (pTyr) signaling plays an important role in regulation of many pathways in cell signaling. Protein complexes regulated by pTyr signaling are key molecular machines in the early processes of signal transduction and therefore the analysis of dynamic protein complexes is critical. Photo-pTyr-scaffold is a chemical proteomics strategy that combines chemical probes with pTyr-recognizing domains to enable the large-scale analysis of pTyr signaling protein complexes in the epidermal growth factor receptor (EGFR) pathway. However, this approach is unable to resolve the one-to-one organization of the identified complexes, increasing the complexity of subsequent complex analysis. In this study, a novel cleavable trifunctional probe was designed and synthesized based on the design of photo-pTyr-scaffold probe, with a cleavable group being introduced into the biotin end of the probe, which enabled controllable elution of the enriched product. Based on the difference in molecular weight of the pTyr signaling protein complexes after cross-linking, sodium dodecyl sulfate-acrylamide gel electrophoresis was used to achieve the separation of the eluted pTyr protein complexes, and the in-gel digestion and mass spectrometry analysis were further performed to identify proteins in different molecular weight regions. Theoretically, the crosslinked pTyr protein complexes would be identified in the regions higher than the original protein molecular weight. With this strategy, the pTyr signaling protein complexes in the EGFR signaling pathway were systematically investigated and the molecular weight migration profiles of 20 important proteins were obtained. And the migration phenomenon was further validated by western blot, demonstrating the feasibility of this approach for analysis of pTyr signaling protein complexes.
Phosphotyrosine (pTyr) signaling plays an important role in regulation of many pathways in cell signaling. Protein complexes regulated by pTyr signaling are key molecular machines in the early processes of signal transduction and therefore the analysis of dynamic protein complexes is critical. Photo-pTyr-scaffold is a chemical proteomics strategy that combines chemical probes with pTyr-recognizing domains to enable the large-scale analysis of pTyr signaling protein complexes in the epidermal growth factor receptor (EGFR) pathway. However, this approach is unable to resolve the one-to-one organization of the identified complexes, increasing the complexity of subsequent complex analysis. In this study, a novel cleavable trifunctional probe was designed and synthesized based on the design of photo-pTyr-scaffold probe, with a cleavable group being introduced into the biotin end of the probe, which enabled controllable elution of the enriched product. Based on the difference in molecular weight of the pTyr signaling protein complexes after cross-linking, sodium dodecyl sulfate-acrylamide gel electrophoresis was used to achieve the separation of the eluted pTyr protein complexes, and the in-gel digestion and mass spectrometry analysis were further performed to identify proteins in different molecular weight regions. Theoretically, the crosslinked pTyr protein complexes would be identified in the regions higher than the original protein molecular weight. With this strategy, the pTyr signaling protein complexes in the EGFR signaling pathway were systematically investigated and the molecular weight migration profiles of 20 important proteins were obtained. And the migration phenomenon was further validated by western blot, demonstrating the feasibility of this approach for analysis of pTyr signaling protein complexes.
2023, 51(4): 502-512
doi: 10.19756/j.issn.0253-3820.221468
Abstract:
Viable quantity and upper gastrointestinal tolerance are two important indicators of probiotic products, which together determine the number of viable bacteria that can eventually colonize in the human intestine. Accurate assessment of these two indicators is essential for guiding consumers to choose probiotic products and for manufacturers to improve product quality. Based on the unique advantages of the laboratory-developed nano-flow cytometry (nFCM) in the sensitive and rapid analysis of individual bacteria, the viable quantities of probiotic powder and upon digestion with simulated gastric juice (SGJ), simulated intestinal juice (SIJ), and simulated upper gastrointestinal tract were measured in this work. Nucleic acid stains SYTO 9 and propidium iodide (PI) were applied to label all the bacteria or dead bacteria with damaged membrane integrity, respectively. The viable quantity and upper gastrointestinal tolerance of 18 kinds of probiotic products (including 16 kinds of powdered products and 2 kinds of capsules) were evaluated. The viable quantity of these 18 products was higher than 1010 cell/package, with an average viable rate of 61.7%. All products met the International Standard for probiotic products (107 cfu/g), but one was lower than the level stated on the label. Then, SGJ at pH=3 and SIJ with bile salt concentration of 0.3% (m/V) were used to examine the tolerance of probiotic products to gastric juice, intestinal juice and upper gastrointestinal tract. By comparing the survival rate after SGJ and SIJ digestion, the products could be divided into two categories. One had stronger gastric juice resistance (12 products), and the other one had stronger intestinal juice resistance (6 products). For most products, over 108 cells/package of probiotics survived after upper gastrointestinal tract digestion, with an average survival rate of 15.6%. Finally, the protection effect of stomach capsules and enteric capsules on probiotics was investigated. The enteric capsules showed gastric protection to probiotics. However, the encapsulated probiotics needed to have strong intestinal tolerance at the same time to improve their survival rate in the upper gastrointestinal tract.
Viable quantity and upper gastrointestinal tolerance are two important indicators of probiotic products, which together determine the number of viable bacteria that can eventually colonize in the human intestine. Accurate assessment of these two indicators is essential for guiding consumers to choose probiotic products and for manufacturers to improve product quality. Based on the unique advantages of the laboratory-developed nano-flow cytometry (nFCM) in the sensitive and rapid analysis of individual bacteria, the viable quantities of probiotic powder and upon digestion with simulated gastric juice (SGJ), simulated intestinal juice (SIJ), and simulated upper gastrointestinal tract were measured in this work. Nucleic acid stains SYTO 9 and propidium iodide (PI) were applied to label all the bacteria or dead bacteria with damaged membrane integrity, respectively. The viable quantity and upper gastrointestinal tolerance of 18 kinds of probiotic products (including 16 kinds of powdered products and 2 kinds of capsules) were evaluated. The viable quantity of these 18 products was higher than 1010 cell/package, with an average viable rate of 61.7%. All products met the International Standard for probiotic products (107 cfu/g), but one was lower than the level stated on the label. Then, SGJ at pH=3 and SIJ with bile salt concentration of 0.3% (m/V) were used to examine the tolerance of probiotic products to gastric juice, intestinal juice and upper gastrointestinal tract. By comparing the survival rate after SGJ and SIJ digestion, the products could be divided into two categories. One had stronger gastric juice resistance (12 products), and the other one had stronger intestinal juice resistance (6 products). For most products, over 108 cells/package of probiotics survived after upper gastrointestinal tract digestion, with an average survival rate of 15.6%. Finally, the protection effect of stomach capsules and enteric capsules on probiotics was investigated. The enteric capsules showed gastric protection to probiotics. However, the encapsulated probiotics needed to have strong intestinal tolerance at the same time to improve their survival rate in the upper gastrointestinal tract.
2023, 51(4): 513-520
doi: 10.19756/j.issn.0253-3820.221526
Abstract:
Single-cell ribonucleic acid (RNA) analysis is necessary to investigate the biological effects of circulating tumor cell clusters (CTC clusters). To achieve the most efficient results in single-cell analysis of CTC clusters, the integrity of the CTC cluster and the high quality of the intracellular RNA should be maintained after the capture and single-cell isolation. So, three house gene was quantitated in single cells for RNA quality control by single-cell RNA sequencing method, and the CTC cluster's lateral diameter for evaluating the CTC cluster's integrity were used to evaluate the quality of CTC cluster capture and single-cell isolation process. Trypsin-EDTA and non-enzymatic cell dissociation solution (NECDS) were used to isolate single cells in CTC clusters, followed by the investigation of intracellular RNA quality. The CTC cluster recovery of negative enrichment, positive enrichment and membrane filtration, and single-cell RNA integrity after enrichment were investigated. The results indicated that the NECDS isolated single cells from CTC clusters rapidly without affecting the intracellular RNA. Besides, it was found that rotational incubation and treatments of red blood cell lysate disrupted the integrity of CTC clusters, therefore, these operations were not the best way for single-cell RNA analysis of CTC clusters. The positive enrichment with simplified process achieved a high recovery without affecting the quality of intracellular RNA. Single-cell RNA analysis of CTC clusters required gentle capture and single-cell isolation process. The present study here provided an efficient sample preparation strategy for single-cell analysis of CTC clusters.
Single-cell ribonucleic acid (RNA) analysis is necessary to investigate the biological effects of circulating tumor cell clusters (CTC clusters). To achieve the most efficient results in single-cell analysis of CTC clusters, the integrity of the CTC cluster and the high quality of the intracellular RNA should be maintained after the capture and single-cell isolation. So, three house gene was quantitated in single cells for RNA quality control by single-cell RNA sequencing method, and the CTC cluster's lateral diameter for evaluating the CTC cluster's integrity were used to evaluate the quality of CTC cluster capture and single-cell isolation process. Trypsin-EDTA and non-enzymatic cell dissociation solution (NECDS) were used to isolate single cells in CTC clusters, followed by the investigation of intracellular RNA quality. The CTC cluster recovery of negative enrichment, positive enrichment and membrane filtration, and single-cell RNA integrity after enrichment were investigated. The results indicated that the NECDS isolated single cells from CTC clusters rapidly without affecting the intracellular RNA. Besides, it was found that rotational incubation and treatments of red blood cell lysate disrupted the integrity of CTC clusters, therefore, these operations were not the best way for single-cell RNA analysis of CTC clusters. The positive enrichment with simplified process achieved a high recovery without affecting the quality of intracellular RNA. Single-cell RNA analysis of CTC clusters required gentle capture and single-cell isolation process. The present study here provided an efficient sample preparation strategy for single-cell analysis of CTC clusters.
2023, 51(4): 521-530
doi: 10.19756/j.issn.0253-3820.221591
Abstract:
By taking advantage of the competitive reaction between Cu2+, Au/Ag bimetallic nanoclusters capped with 11-mercaptoundecanoic acid (AuAgNCs@11-MUA) and glyphosate, a simple and sensitive " turn-on" fluorescence method was devised for glyphosate detection. The fluorescence of AuAgNCs@11-MUA could be selectively quenched by Cu2+ owing to the binding between Cu2+ and carboxyl groups of AuAgNCs@11-MUA. Due to the specific interaction between Cu2+ and functional groups of glyphosate, the pre-incubation of Cu2+ and glyphosate could disturb the combination of Cu2+ and AuAgNCs@11-MUA and AuAgNCs@11-MUA emitted intense fluorescence again, and thus glyphosate could be quantitatively detected. The optimum pH was 7.0 and the incubation time of Cu2+ and glyphosate was 2 min. Under the optimized conditions, the developed method showed a good linear relationship for detection of glyphosate in the concentration range of 0.025-1.0 μg/mL, with an inspiring detection limit as low as 8 ng/mL. In addition, an " Implication" logic gate was rationally devised by employing Cu2+ and glyphosate as inputs. Such unprecedented " turn-on" analytical proposal possessed many advantages such as fast response time, high selectivity and sensitivity. The AuAgNCs@11-MUA-Cu2+ system could be used for detection of glyphosate in actual water samples with satisfactory results.
By taking advantage of the competitive reaction between Cu2+, Au/Ag bimetallic nanoclusters capped with 11-mercaptoundecanoic acid (AuAgNCs@11-MUA) and glyphosate, a simple and sensitive " turn-on" fluorescence method was devised for glyphosate detection. The fluorescence of AuAgNCs@11-MUA could be selectively quenched by Cu2+ owing to the binding between Cu2+ and carboxyl groups of AuAgNCs@11-MUA. Due to the specific interaction between Cu2+ and functional groups of glyphosate, the pre-incubation of Cu2+ and glyphosate could disturb the combination of Cu2+ and AuAgNCs@11-MUA and AuAgNCs@11-MUA emitted intense fluorescence again, and thus glyphosate could be quantitatively detected. The optimum pH was 7.0 and the incubation time of Cu2+ and glyphosate was 2 min. Under the optimized conditions, the developed method showed a good linear relationship for detection of glyphosate in the concentration range of 0.025-1.0 μg/mL, with an inspiring detection limit as low as 8 ng/mL. In addition, an " Implication" logic gate was rationally devised by employing Cu2+ and glyphosate as inputs. Such unprecedented " turn-on" analytical proposal possessed many advantages such as fast response time, high selectivity and sensitivity. The AuAgNCs@11-MUA-Cu2+ system could be used for detection of glyphosate in actual water samples with satisfactory results.
2023, 51(4): 531-538
doi: 10.19756/j.issn.0253-3820.221311
Abstract:
Water soluble bovine serum albumin-gold nanoclusters (BSA-AuNCs) with good fluorescence properties were synthesized using BSA as template. According to the highly selective fluorescence response of methacycline (MTC) to BSA-AuNCs, a rapid and highly sensitive detection method for residual MTC in water was constructed on the basis of the highly selective fluorescence response of MTC to BSA-AuNCs and the fluorescence sensitization of non-ionic surfactant Tween 20. In the presence of MTC, the green fluorescence intensity at 525 nm was significantly increased and the red fluorescence intensity at 670 nm was slightly changed in comparison with BSA-AuNCs. Furthermore, it was observed that the ratiometric signal (F525/F670) of the detection system was obviously sensitized by non-ionic surfactants. Under the optimal experimental conditions, the linear concentration range of the system for MTC was 1-100 nmol/L, and the detection limit (LOD) was 0.71 nmol/L. In addition, the recoveries of MTC in the spiked water samples were 97%-108% with a relative standard deviations (RSD) lower than 10%. The developed fluorescent probe here could be used for simple, rapid, cost-effective, highly sensitive and selective detection of MTC in real applications.
Water soluble bovine serum albumin-gold nanoclusters (BSA-AuNCs) with good fluorescence properties were synthesized using BSA as template. According to the highly selective fluorescence response of methacycline (MTC) to BSA-AuNCs, a rapid and highly sensitive detection method for residual MTC in water was constructed on the basis of the highly selective fluorescence response of MTC to BSA-AuNCs and the fluorescence sensitization of non-ionic surfactant Tween 20. In the presence of MTC, the green fluorescence intensity at 525 nm was significantly increased and the red fluorescence intensity at 670 nm was slightly changed in comparison with BSA-AuNCs. Furthermore, it was observed that the ratiometric signal (F525/F670) of the detection system was obviously sensitized by non-ionic surfactants. Under the optimal experimental conditions, the linear concentration range of the system for MTC was 1-100 nmol/L, and the detection limit (LOD) was 0.71 nmol/L. In addition, the recoveries of MTC in the spiked water samples were 97%-108% with a relative standard deviations (RSD) lower than 10%. The developed fluorescent probe here could be used for simple, rapid, cost-effective, highly sensitive and selective detection of MTC in real applications.
2023, 51(4): 539-548
doi: 10.19756/j.issn.0253-3820.221149
Abstract:
The development of rapid and simple electrochemical sensing technology for detection of chloramphenicol (CAP) has important application prospects in food safety and environmental monitoring. Herein, NH2-MIL-88(Fe) was successfully synthesized by a hydrothermal method using FeCl3∙·6H2O and 2-aminoterephthalic acid (2-ATPA) as the starting materials. Then, the NH2-MIL-88(Fe) was covalently anchored on the surface of carboxylated glassy carbon electrode through the amino group on 2-ATPA. Furthermore, the 5'-PO43- modified chloramphenicol aptamer (C-Apt) was self-assembled on the NH2-MIL-88(Fe) surface through the coordination between -PO43- and Fe3+ to construct a novel label-free electrochemical biosensing interface. The immobilization of C-Apt did not need any crosslinking agent or pre-treatment. Electrochemical assays showed that the NH2-MIL-88(Fe) modified electrode had strong catalytic activity for 3,3',5,5'-tetramethylbenzidine (TMB)/H2O2 system due to the nano enzymetic activity of NH2-MIL-88(Fe); while the catalytic activity could be inhibited after forming a barrier layer that generated by the capture of CAP by C-Apt, through which the target CAP could be detected through the label-free method. The quantitative analysis results showed that the catalytic current (Ip) for the oxidation of TMB/H2O2 system had a good linear relationship with the negative logarithm of CAP concentration (-lgC) within the concentration range of 1.0 pmol/L -0.1 μmol/L, and the detection limit was as low as 330 fmol/L (S/N=3). The biosensor could be used for detection of CAP residue in actual milk samples, which provided a new idea for the rapid detection of CAP residue in the food field.
The development of rapid and simple electrochemical sensing technology for detection of chloramphenicol (CAP) has important application prospects in food safety and environmental monitoring. Herein, NH2-MIL-88(Fe) was successfully synthesized by a hydrothermal method using FeCl3∙·6H2O and 2-aminoterephthalic acid (2-ATPA) as the starting materials. Then, the NH2-MIL-88(Fe) was covalently anchored on the surface of carboxylated glassy carbon electrode through the amino group on 2-ATPA. Furthermore, the 5'-PO43- modified chloramphenicol aptamer (C-Apt) was self-assembled on the NH2-MIL-88(Fe) surface through the coordination between -PO43- and Fe3+ to construct a novel label-free electrochemical biosensing interface. The immobilization of C-Apt did not need any crosslinking agent or pre-treatment. Electrochemical assays showed that the NH2-MIL-88(Fe) modified electrode had strong catalytic activity for 3,3',5,5'-tetramethylbenzidine (TMB)/H2O2 system due to the nano enzymetic activity of NH2-MIL-88(Fe); while the catalytic activity could be inhibited after forming a barrier layer that generated by the capture of CAP by C-Apt, through which the target CAP could be detected through the label-free method. The quantitative analysis results showed that the catalytic current (Ip) for the oxidation of TMB/H2O2 system had a good linear relationship with the negative logarithm of CAP concentration (-lgC) within the concentration range of 1.0 pmol/L -0.1 μmol/L, and the detection limit was as low as 330 fmol/L (S/N=3). The biosensor could be used for detection of CAP residue in actual milk samples, which provided a new idea for the rapid detection of CAP residue in the food field.
2023, 51(4): 549-558
doi: 10.19756/j.issn.0253-3820.221338
Abstract:
An enzyme-free molecularly imprinted electrochemical sensor was constructed for highly sensitive determination of glucose. The molecular imprinting polymer was electro-deposited on the surface of carbon quantum dots and chitosan modified glassy carbon electrode using 3-aminobenzeneboronic acid as functional monomer and glucose as template molecule. The electrochemical and analytical characteristics of the sensor were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. Under the optimal conditions, variation of the peak current of the sensor showed good linear correlation with the glucose concentration in the range of 0.1-1.0 μmol/L and 1.0-300 μmol/L, respectively. The linear regression equations were ΔIp (μA)=3.792 + 23.41C (R2=0.9968) and ΔIp (μA)=28.18 +0.1316C (R2=0.9914), respectively, with a detection limit of 0.034 μmol/L (3σ/k). The method exhibited potential application in detection of glucose in body fluids with recoveries of 95.1%-106.8%.
An enzyme-free molecularly imprinted electrochemical sensor was constructed for highly sensitive determination of glucose. The molecular imprinting polymer was electro-deposited on the surface of carbon quantum dots and chitosan modified glassy carbon electrode using 3-aminobenzeneboronic acid as functional monomer and glucose as template molecule. The electrochemical and analytical characteristics of the sensor were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. Under the optimal conditions, variation of the peak current of the sensor showed good linear correlation with the glucose concentration in the range of 0.1-1.0 μmol/L and 1.0-300 μmol/L, respectively. The linear regression equations were ΔIp (μA)=3.792 + 23.41C (R2=0.9968) and ΔIp (μA)=28.18 +0.1316C (R2=0.9914), respectively, with a detection limit of 0.034 μmol/L (3σ/k). The method exhibited potential application in detection of glucose in body fluids with recoveries of 95.1%-106.8%.
2023, 51(4): 559-569
doi: 10.19756/j.issn.0253-3820.221297
Abstract:
N-doped cobalt metal organic framework (N-Co-MOF) was synthesized by solvothermal method using trimesic acid as ligand and Co2+ and polyvinyl pyrrolidone (PVP) as central metal ions and nitrogen source. The morphology and composition of the materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The electrochemical sensor for detection of clenbuterol (CLB) was constructed on glassy carbon electrode (GCE) modified with N-Co-MOF. The cyclic voltammetry (CV) characterization results showed that the N-Co-MOF could provide more electrochemical active sites and significantly improve the electron transfer ability, and had good electrocatalytic oxidation activity for CLB. The linear range of the sensor for CLB was 0.01-29.5 μmol/L, and the detection limit (3σ) was 4.6 nmol/L. The sensor had excellent anti-interference performance, good reproducibility and stability, and had good accuracy in detection of CLB in actual meat samples, with recoveries of 98.5%-102.9%.
N-doped cobalt metal organic framework (N-Co-MOF) was synthesized by solvothermal method using trimesic acid as ligand and Co2+ and polyvinyl pyrrolidone (PVP) as central metal ions and nitrogen source. The morphology and composition of the materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The electrochemical sensor for detection of clenbuterol (CLB) was constructed on glassy carbon electrode (GCE) modified with N-Co-MOF. The cyclic voltammetry (CV) characterization results showed that the N-Co-MOF could provide more electrochemical active sites and significantly improve the electron transfer ability, and had good electrocatalytic oxidation activity for CLB. The linear range of the sensor for CLB was 0.01-29.5 μmol/L, and the detection limit (3σ) was 4.6 nmol/L. The sensor had excellent anti-interference performance, good reproducibility and stability, and had good accuracy in detection of CLB in actual meat samples, with recoveries of 98.5%-102.9%.
2023, 51(4): 570-578
doi: 10.19756/j.issn.0253-3820.221258
Abstract:
Fingerprints, as one of the most important evidences, contain numerous personal information and are used for individual identification in the field of forensic science. However, in real case scenes, traditional way of comparison and matching with patterns may not be effective, as the detected fingerprints are mostly fuzzy or incomplete. Additionally, the compositions of fingerprint substance are so complicated that it is quite difficult to characterize donors according to some specific compounds. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) can obtain the mass spectra of fingerprint substances and corresponding ion distribution images without destroying the patterns, which provides the possibility of identifying individuals based on fingerprint substances. In this study, the mass spectra of ten fingerprints from 5 volunteers were collected using TOF-SIMS to preliminarily explore the feasibility of identifying individuals based on ion signals of fingerprint substance. Firstly, 98 kinds of TOF-SIMS ion signals representing different fingerprint substances were screened out followed by the process of principal component analysis to reduce the dimension of intensity of ion signals. Afterwards, the newly saved variables after dimension reduction were input into different classifiers to compare the effects. The results showed that the effect of unsupervised hierarchical clustering was quite different from the actual classification, while supervised Fisher discriminant method could correctly discriminate 94% of the individuals and the accuracy of cross-validation also reached 90%. Meanwhile, more ideal results would be achieved when the data was input into the multi-layer perceptron neural network after multiple trainings. The individual classification and prediction models were established via various statistical analysis methods, which provided a new channel for improving the evidence value of fingerprints and laid the research foundation for further exploration of employing fingerprint substances to identify individuals.
Fingerprints, as one of the most important evidences, contain numerous personal information and are used for individual identification in the field of forensic science. However, in real case scenes, traditional way of comparison and matching with patterns may not be effective, as the detected fingerprints are mostly fuzzy or incomplete. Additionally, the compositions of fingerprint substance are so complicated that it is quite difficult to characterize donors according to some specific compounds. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) can obtain the mass spectra of fingerprint substances and corresponding ion distribution images without destroying the patterns, which provides the possibility of identifying individuals based on fingerprint substances. In this study, the mass spectra of ten fingerprints from 5 volunteers were collected using TOF-SIMS to preliminarily explore the feasibility of identifying individuals based on ion signals of fingerprint substance. Firstly, 98 kinds of TOF-SIMS ion signals representing different fingerprint substances were screened out followed by the process of principal component analysis to reduce the dimension of intensity of ion signals. Afterwards, the newly saved variables after dimension reduction were input into different classifiers to compare the effects. The results showed that the effect of unsupervised hierarchical clustering was quite different from the actual classification, while supervised Fisher discriminant method could correctly discriminate 94% of the individuals and the accuracy of cross-validation also reached 90%. Meanwhile, more ideal results would be achieved when the data was input into the multi-layer perceptron neural network after multiple trainings. The individual classification and prediction models were established via various statistical analysis methods, which provided a new channel for improving the evidence value of fingerprints and laid the research foundation for further exploration of employing fingerprint substances to identify individuals.
2023, 51(4): 579-588
doi: 10.19756/j.issn.0253-3820.221413
Abstract:
The treatment mechanism of depression of model mice induced by chronic unpredictable mild stress (CUMS) using Chaihuyujinxiang granules (CHYJX) was investigated by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), which laid a theoretical foundation for the clinical treatment of depression using CHYJX. A total of 1266 endogenous metabolites were identified in mouse plasma. Based on univariate statistical analysis, there were significant differences in metabolites between the blank group and the model group, and between the model group and the CHYJX treatment group. The results of principal component analysis (PCA) of multidimensional statistical analysis showed that there was a clear trend of difference between the blank group, the model group and the CHYJX treatment group. The orthogonal partial least squares discriminant analysis method (OPLS-DA) could clearly distinguish the blank group and the model group, and the model group and the CHYJX treatment group, and 57 and 89 differential metabolites were screened out, respectively, of which 13 differential metabolites had opposite trends in the two contrast modes. The pathway enrichment analysis of these 13 differential metabolites showed that GABAergic synapses, neural active ligand receptor interactions, synaptic vesicle circulation, 5-hydroxytryptaminergic and dopaminergic synapses, sphingolipid metabolism, phenylalanine and tyrosine, tryptophan biosynthesis, and phenylalanine metabolic pathway had significant changes. The pathogenesis of depression was closely related to neural activity. The results of this study indicated that the mechanism of CHYJX in the treatment of CUMS and solitary-induced depression model mice was closely related to these eight signaling pathways.
The treatment mechanism of depression of model mice induced by chronic unpredictable mild stress (CUMS) using Chaihuyujinxiang granules (CHYJX) was investigated by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), which laid a theoretical foundation for the clinical treatment of depression using CHYJX. A total of 1266 endogenous metabolites were identified in mouse plasma. Based on univariate statistical analysis, there were significant differences in metabolites between the blank group and the model group, and between the model group and the CHYJX treatment group. The results of principal component analysis (PCA) of multidimensional statistical analysis showed that there was a clear trend of difference between the blank group, the model group and the CHYJX treatment group. The orthogonal partial least squares discriminant analysis method (OPLS-DA) could clearly distinguish the blank group and the model group, and the model group and the CHYJX treatment group, and 57 and 89 differential metabolites were screened out, respectively, of which 13 differential metabolites had opposite trends in the two contrast modes. The pathway enrichment analysis of these 13 differential metabolites showed that GABAergic synapses, neural active ligand receptor interactions, synaptic vesicle circulation, 5-hydroxytryptaminergic and dopaminergic synapses, sphingolipid metabolism, phenylalanine and tyrosine, tryptophan biosynthesis, and phenylalanine metabolic pathway had significant changes. The pathogenesis of depression was closely related to neural activity. The results of this study indicated that the mechanism of CHYJX in the treatment of CUMS and solitary-induced depression model mice was closely related to these eight signaling pathways.
2023, 51(4): 589-599
doi: 10.19756/j.issn.0253-3820.221387
Abstract:
A headspace-gas chromatography-quadrupole/orbitrap high resolution mass spectrometry (HS-GC-Q/OrbitrapHRMS) for determination of 56 kinds of volatile organic compounds (VOCs) in complex matrix waters was developed. By optimizing the conditions of injection delay time of headspace injector and inlet temperature of gas chromatograph, the sample condensation of high-boiling analytes inside the syringe's needle was eliminated. A TG-5SILMS chromatographic column was used for separation, the data were collected by electron ionization (EI) sources under the full scan mode, and the analytes were quantified by using dichloromethane-D2 and fluorobenzene as internal standards. In a 10-mL test sample, sodium chloride (NaCl) concentration was 30% (m/V) and methanol concentration should be below 3% (V/V). The calibration curves of 56 compounds showed good linearity in the concentration ranges of 0.2-10 μg/L (R2>0.998) and 10-200 μg/L (R2>0.995). The recoveries ranged from 83.5% to 129.0% at three spiked levels (2, 10 and 100 μg/L), while the relative standard deviations (RSD) ranged from 0.4% to 13.0%. The limits of detection and limits of quantification were 0.01-0.17 μg/L and 0.05-0.69 μg/L, respectively. In the 99% confidence interval, the measurements of reference material (RM) of VOCs in groundwater with high bicarbonate and natural organic matter showed that there was no significant difference among the results of this method and those of the RM's property values. The detection method with high sensitivity and precision was superior to the current detection methods, and suitable for determining VOCs in water samples which could not introduce to GC-MS system by P&T samplers.
A headspace-gas chromatography-quadrupole/orbitrap high resolution mass spectrometry (HS-GC-Q/OrbitrapHRMS) for determination of 56 kinds of volatile organic compounds (VOCs) in complex matrix waters was developed. By optimizing the conditions of injection delay time of headspace injector and inlet temperature of gas chromatograph, the sample condensation of high-boiling analytes inside the syringe's needle was eliminated. A TG-5SILMS chromatographic column was used for separation, the data were collected by electron ionization (EI) sources under the full scan mode, and the analytes were quantified by using dichloromethane-D2 and fluorobenzene as internal standards. In a 10-mL test sample, sodium chloride (NaCl) concentration was 30% (m/V) and methanol concentration should be below 3% (V/V). The calibration curves of 56 compounds showed good linearity in the concentration ranges of 0.2-10 μg/L (R2>0.998) and 10-200 μg/L (R2>0.995). The recoveries ranged from 83.5% to 129.0% at three spiked levels (2, 10 and 100 μg/L), while the relative standard deviations (RSD) ranged from 0.4% to 13.0%. The limits of detection and limits of quantification were 0.01-0.17 μg/L and 0.05-0.69 μg/L, respectively. In the 99% confidence interval, the measurements of reference material (RM) of VOCs in groundwater with high bicarbonate and natural organic matter showed that there was no significant difference among the results of this method and those of the RM's property values. The detection method with high sensitivity and precision was superior to the current detection methods, and suitable for determining VOCs in water samples which could not introduce to GC-MS system by P&T samplers.
2023, 51(4): 600-610
doi: 10.19756/j.issn.0253-3820.221587
Abstract:
Molecularly imprinted polymers (MIPs), known as ″artificial antibodies″, are widely used in extraction and separation of natural pharmaceutical active ingredients due to the high selectivity. To enhance the extraction efficiency and the affinity of imprinted pores for target molecules, a novel type of boronic acid-affinity magnetic molecularly imprinted polymers (RT-PBA/MMIPs) was prepared using phenylboronic acid (PBA)-modified magnetic spheres (PBA/MSN) as the carrier, RT as the template molecule, and dopamine (DA) as the functional monomer, while boronic acid affinity and two-step template immobilization strategies were synergistically applied at the same time. Through a series of physical and chemical characterizations, it was verified that the prepared RT-PBA/MMIPs had uniform particle size, stable crystal form, and excellent magnetic properties. Meanwhile, kinetic, thermodynamic and selective adsorption experiments demonstrated that RT-PBA/MMIPs had fast adsorption speed (6 min to reach adsorption equilibrium), high adsorption capacity (Q=2.04 mg/g), and good selectivity (IF=2.43) and reusability (the adsorption efficiency was higher than 94.43% after 6 adsorptiondesorption cycles). In addition, RT-PBA/MMIPs were used as a solid-phase extraction adsorbent in combination with high performance liquid chromatography to achieve efficient extraction and enrichment of RT from Sophora japonica with recoveries of 83.1%-92.3%. In a word, the developed RT-PBA/MMIPs showed good practical application prospects and were expected to be used for the rapid and selective separation and extraction of RT as well as other active ingredients of natural medicines.
Molecularly imprinted polymers (MIPs), known as ″artificial antibodies″, are widely used in extraction and separation of natural pharmaceutical active ingredients due to the high selectivity. To enhance the extraction efficiency and the affinity of imprinted pores for target molecules, a novel type of boronic acid-affinity magnetic molecularly imprinted polymers (RT-PBA/MMIPs) was prepared using phenylboronic acid (PBA)-modified magnetic spheres (PBA/MSN) as the carrier, RT as the template molecule, and dopamine (DA) as the functional monomer, while boronic acid affinity and two-step template immobilization strategies were synergistically applied at the same time. Through a series of physical and chemical characterizations, it was verified that the prepared RT-PBA/MMIPs had uniform particle size, stable crystal form, and excellent magnetic properties. Meanwhile, kinetic, thermodynamic and selective adsorption experiments demonstrated that RT-PBA/MMIPs had fast adsorption speed (6 min to reach adsorption equilibrium), high adsorption capacity (Q=2.04 mg/g), and good selectivity (IF=2.43) and reusability (the adsorption efficiency was higher than 94.43% after 6 adsorptiondesorption cycles). In addition, RT-PBA/MMIPs were used as a solid-phase extraction adsorbent in combination with high performance liquid chromatography to achieve efficient extraction and enrichment of RT from Sophora japonica with recoveries of 83.1%-92.3%. In a word, the developed RT-PBA/MMIPs showed good practical application prospects and were expected to be used for the rapid and selective separation and extraction of RT as well as other active ingredients of natural medicines.
2023, 51(4): 611-620
doi: 10.19756/j.issn.0253-3820.221455
Abstract:
A solid phase extraction-solid phase assisted derivatization (SPE-SPAD) method combined with gas chromatography-tandem mass spectrometry analysis was established for qualitative and quantitative detection of trace cyanide in environmental samples and biological samples. The cyanide ion was transformed to cyanogen chloride via chloramine T. Next, the process of enrichment, purification and derivatization for reactants were simultaneously archived on the C8 solid phase extraction (SPE) column. The types of SPE column and the solvent of reaction were optimized for the derivatization. The structure of derivative was identified as n-butyl thiocyanate by gas chromatography-mass spectrometry and nuclear magnetic resonance. The qualitative and quantitative detection method for cyanide in water and urine samples was established by gas chromatography-selective reaction monitoring (SRM) mode via isopropyl disulfide as internal standard. The established method had high sensitivity, good specificity and shorter time of sample preparation. The linear ranges for detection of cyanide in water and urine samples were 10-1000 ng/mL and 10-800 ng/mL, with detection limits of 7.0 and 8.0 ng/mL (S/N=3), respectively. The intra- and inter-day precisions were 4.2%-7.8% (n=3) and 5.2%-7.9% (n=6), respectively. The method was successfully applied to determine the cyanide in urine samples from the 2nd Biological Proficiency Test, which was organized by the Organization for the Prohibition of Chemical Weapons (OPCW), and the average recovery was 97.7%. The wastewater from the Tianjin port after the explosion was detected and the concentration of cyanide was about 1.9 mg/mL. The established method was effective for screening and identification of trace cyanide, and had great potential in chemical accident rescue and chemical weapons verification.
A solid phase extraction-solid phase assisted derivatization (SPE-SPAD) method combined with gas chromatography-tandem mass spectrometry analysis was established for qualitative and quantitative detection of trace cyanide in environmental samples and biological samples. The cyanide ion was transformed to cyanogen chloride via chloramine T. Next, the process of enrichment, purification and derivatization for reactants were simultaneously archived on the C8 solid phase extraction (SPE) column. The types of SPE column and the solvent of reaction were optimized for the derivatization. The structure of derivative was identified as n-butyl thiocyanate by gas chromatography-mass spectrometry and nuclear magnetic resonance. The qualitative and quantitative detection method for cyanide in water and urine samples was established by gas chromatography-selective reaction monitoring (SRM) mode via isopropyl disulfide as internal standard. The established method had high sensitivity, good specificity and shorter time of sample preparation. The linear ranges for detection of cyanide in water and urine samples were 10-1000 ng/mL and 10-800 ng/mL, with detection limits of 7.0 and 8.0 ng/mL (S/N=3), respectively. The intra- and inter-day precisions were 4.2%-7.8% (n=3) and 5.2%-7.9% (n=6), respectively. The method was successfully applied to determine the cyanide in urine samples from the 2nd Biological Proficiency Test, which was organized by the Organization for the Prohibition of Chemical Weapons (OPCW), and the average recovery was 97.7%. The wastewater from the Tianjin port after the explosion was detected and the concentration of cyanide was about 1.9 mg/mL. The established method was effective for screening and identification of trace cyanide, and had great potential in chemical accident rescue and chemical weapons verification.
2023, 51(4): 621-628
doi: 10.19756/j.issn.0253-3820.221466
Abstract:
The nanoscale organisation and transformation of self-assembled lipid membranes is central to the biological function of cell analysis and bionic structure construction as well as the biosensor research. While lots of work have focused on chemical interactions of component within the membrane, limited results address the impact of a trans-membrane potential on the molecular behaviour of the lipids and the related effects, especially in physiological media solutions. Here, in a salt solution that was isotonic to the physiological medium and utilizing a combination of atomic force microscopy (AFM) and fluorescence recovery after photobleaching (FRAP) techniques, the nanoscale molecular arrangement, assemble of neutral and charged lipids at the surface of highly ordered pyrolytic graphite (HOPG) and its structure transition under electrical potentials were studied. The results showed that these lipids were spread on HOPG in the form of monolayers at gel-phase because of the hydrophobic effect between substrate and lipid legs at room temperature. These lipids further assembled to form nanoscale semimicellar structures and exhibited corrugations morphology in AFM images. When a moderate electric field (±1.0 V) was applied on HOPG substrate, it was found to play a major role in inducing the arrangement of lipid molecules and structural transformation, while interfacial solvation forces and ion effects played a minor role. This work provided reference for the simulation of bioelectrochemical devices and the development of phospholipidbased macromolecule laboratory chips.
The nanoscale organisation and transformation of self-assembled lipid membranes is central to the biological function of cell analysis and bionic structure construction as well as the biosensor research. While lots of work have focused on chemical interactions of component within the membrane, limited results address the impact of a trans-membrane potential on the molecular behaviour of the lipids and the related effects, especially in physiological media solutions. Here, in a salt solution that was isotonic to the physiological medium and utilizing a combination of atomic force microscopy (AFM) and fluorescence recovery after photobleaching (FRAP) techniques, the nanoscale molecular arrangement, assemble of neutral and charged lipids at the surface of highly ordered pyrolytic graphite (HOPG) and its structure transition under electrical potentials were studied. The results showed that these lipids were spread on HOPG in the form of monolayers at gel-phase because of the hydrophobic effect between substrate and lipid legs at room temperature. These lipids further assembled to form nanoscale semimicellar structures and exhibited corrugations morphology in AFM images. When a moderate electric field (±1.0 V) was applied on HOPG substrate, it was found to play a major role in inducing the arrangement of lipid molecules and structural transformation, while interfacial solvation forces and ion effects played a minor role. This work provided reference for the simulation of bioelectrochemical devices and the development of phospholipidbased macromolecule laboratory chips.
