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2022 Volume 50 Issue 7
2022, 50(7): 973-984
doi: 10.19756/j.issn.0253-3820.221037
Abstract:
At present, the drug situation at home and abroad is still severe. The development of new drugs is extremely fast, the levels of concealment and complexity of drug-related cases are increasing, and the mechanism of drug addiction is still unclear. Therefore, it is urgent to develop advanced drug analytical methods to deal with the above international problems. Mass spectrometry imaging technology has both molecular identification and imaging functions, providing a new analytical method and research horizon for drug research. Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), as a typical representative of mass spectrometry imaging technology, has been widely used in drug-related basic scientific research and detection method development. In this paper, the applications of MALDI-MSI in drug addiction mechanism, forensic drug analysis and drug original plant research were reviewed. The future directions and applications of this technology in the drug-related research were also discussed.
At present, the drug situation at home and abroad is still severe. The development of new drugs is extremely fast, the levels of concealment and complexity of drug-related cases are increasing, and the mechanism of drug addiction is still unclear. Therefore, it is urgent to develop advanced drug analytical methods to deal with the above international problems. Mass spectrometry imaging technology has both molecular identification and imaging functions, providing a new analytical method and research horizon for drug research. Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), as a typical representative of mass spectrometry imaging technology, has been widely used in drug-related basic scientific research and detection method development. In this paper, the applications of MALDI-MSI in drug addiction mechanism, forensic drug analysis and drug original plant research were reviewed. The future directions and applications of this technology in the drug-related research were also discussed.
2022, 50(7): 985-994
doi: 10.19756/j.issn.0253-3820.210722
Abstract:
Single-cell RNA sequencing technology is a high-throughput sequencing technology developed in recent years. It can study cellular gene expression and identify cell heterogeneity at the single cell level, broadening people's understanding of skin development, tumor generation and immune response. Single-cell RNA sequencing studies in skin have systematically revealed the heterogeneity of skin cells, elucidated the pathogenesis of various skin diseases, and identified potential new therapeutic targets for a variety of clinical skin diseases, thus providing guidance for diagnosis and treatment. This article reviewed in detail the single-cell RNA sequencing technology and the latest research progress of this technology in the field of dermatology, aiming to improve the treatment level of skin diseases, and discussed the main challenges for the future development of this field.
Single-cell RNA sequencing technology is a high-throughput sequencing technology developed in recent years. It can study cellular gene expression and identify cell heterogeneity at the single cell level, broadening people's understanding of skin development, tumor generation and immune response. Single-cell RNA sequencing studies in skin have systematically revealed the heterogeneity of skin cells, elucidated the pathogenesis of various skin diseases, and identified potential new therapeutic targets for a variety of clinical skin diseases, thus providing guidance for diagnosis and treatment. This article reviewed in detail the single-cell RNA sequencing technology and the latest research progress of this technology in the field of dermatology, aiming to improve the treatment level of skin diseases, and discussed the main challenges for the future development of this field.
2022, 50(7): 995-1004
doi: 10.19756/j.issn.0253-3820.210894
Abstract:
The improvement of sensor selection recognition ability is crucial to the performance of molecular imprinted sensors. Herein, a molecularly imprinted polymer-based sensor was developed for L-penicillamine (L-Pen) detection based on covalent organic framework compounds COF-JUZ2. The molecular imprint chiral recognition sensor with efficient separation and recognition ability was constructed via selectively fixing the conformation of chiral molecules by COF-JUZ2 to increase the recognition sites. The sensor showed the optimal detection performance for L-Pen when using the mixed solution of ultrapure water, acetic acid and methanol (1:1:8, V/V) as eluant and the COF-JUZ2-CS deposition time, electropolymerization cycle, eluent time and rebind time were 300 s, 15, 5 and 30 min, respectively. The sensor showed an excellent linear relationship with L-Pen concentration in the range of 1.0×10-15 to 1.0×10-9 mol/L, with a detection limit of 7.91×10-16 mol/L. Due to introduction of COF-JUZ2, the separation and recognition performance of the sensor for D-Pen and L-Pen was increased by 13.4 folds. The sensor was applied to determination of L-Pen in real sample, with recoveries of 92.0%-102.0%.
The improvement of sensor selection recognition ability is crucial to the performance of molecular imprinted sensors. Herein, a molecularly imprinted polymer-based sensor was developed for L-penicillamine (L-Pen) detection based on covalent organic framework compounds COF-JUZ2. The molecular imprint chiral recognition sensor with efficient separation and recognition ability was constructed via selectively fixing the conformation of chiral molecules by COF-JUZ2 to increase the recognition sites. The sensor showed the optimal detection performance for L-Pen when using the mixed solution of ultrapure water, acetic acid and methanol (1:1:8, V/V) as eluant and the COF-JUZ2-CS deposition time, electropolymerization cycle, eluent time and rebind time were 300 s, 15, 5 and 30 min, respectively. The sensor showed an excellent linear relationship with L-Pen concentration in the range of 1.0×10-15 to 1.0×10-9 mol/L, with a detection limit of 7.91×10-16 mol/L. Due to introduction of COF-JUZ2, the separation and recognition performance of the sensor for D-Pen and L-Pen was increased by 13.4 folds. The sensor was applied to determination of L-Pen in real sample, with recoveries of 92.0%-102.0%.
2022, 50(7): 1005-1013
doi: 10.19756/j.issn.0253-3820.221076
Abstract:
A "turn-on" fluorescence probe was developed based on terephthalic acid functionalized graphene quantum dots (TPA@GQDs) for highly selective detection of Fe2+. The TPA@GQDs were prepared by a one-step hydrothermal method using GO as carbon source and terephthalic acid as modifying group, where potassium hydroxide served as the cutting agent and hydrogen peroxide as the auxiliary cutting agent. The structure and component of TPA@GQDs were studied by a variety of characterization methods, and the optical properties and feasibility of TPA@GQDs as a fluorescent probe were further explored. Based on the electron-donating function of Fe2+ to induce the fluorescence enhancement of TPA@GQDs, a "turn-on" fluorescent probe was constructed for sensitive detection of Fe2+. The linear ranges were from 0.33 to 20 μmol/L and 20 to 60 μmol/L, with the limit of detection (3σ) of 0.33 μmol/L, and the corresponding linear equations were F/F0=0.0638C+1.1385 (R2=0.9974) and F/F0=0.0244C+1.9215 (R2=0.9989), respectively. Moreover, this system demonstrated good selectivity toward Fe2+, and Fe3+ had no effect on the detection of Fe2+. Finally, the proposed probe was applied to accurate determination of Fe2+ in underground water with recoveries of 98.5%-102.0%, showing broad application prospects in water quality monitoring.
A "turn-on" fluorescence probe was developed based on terephthalic acid functionalized graphene quantum dots (TPA@GQDs) for highly selective detection of Fe2+. The TPA@GQDs were prepared by a one-step hydrothermal method using GO as carbon source and terephthalic acid as modifying group, where potassium hydroxide served as the cutting agent and hydrogen peroxide as the auxiliary cutting agent. The structure and component of TPA@GQDs were studied by a variety of characterization methods, and the optical properties and feasibility of TPA@GQDs as a fluorescent probe were further explored. Based on the electron-donating function of Fe2+ to induce the fluorescence enhancement of TPA@GQDs, a "turn-on" fluorescent probe was constructed for sensitive detection of Fe2+. The linear ranges were from 0.33 to 20 μmol/L and 20 to 60 μmol/L, with the limit of detection (3σ) of 0.33 μmol/L, and the corresponding linear equations were F/F0=0.0638C+1.1385 (R2=0.9974) and F/F0=0.0244C+1.9215 (R2=0.9989), respectively. Moreover, this system demonstrated good selectivity toward Fe2+, and Fe3+ had no effect on the detection of Fe2+. Finally, the proposed probe was applied to accurate determination of Fe2+ in underground water with recoveries of 98.5%-102.0%, showing broad application prospects in water quality monitoring.
A Novel Fluorescent Peptide Probe for Specific Detection of Gadolinium Ion(Ⅲ) in Cells and Zebrafish
2022, 50(7): 1014-1021
doi: 10.19756/j.issn.0253-3820.221056
Abstract:
As the most widely used magnetic resonance imaging contrast in clinical applications, gadolinium-based contrast agents play an important role in the clinical diagnosis and related research, while gadolinium deposition has been found to be closely related to nephrogenic systemic fibrosis and may cause multiple sclerosis, neurofibromatosis, inborn error of metabolism and other diseases. Therefore, the development of efficient assays for free Gd3+ is critical for the mechanistic study of these diseases. In this work, the fluorescent peptide probe PT consisted of (TPE-Glu-Glu-Glu-Pro-Gly-Glu-Glu-Glu) sequences was reported. The results showed that the efficient detection of Gd3+ in solution and biological fluids using the TPE-modified peptide probe PT without interferences of other metal ions was achieved. Meanwhile, the Job's analysis result indicated that the probe PT and Gd3+ formed a 1:3 complex and recovered its fluorescence, with a binding constant of 2.34×1015 L3/mol3. It was demonstrated that the fluorescent peptide probe PT provided a "Turn-On" sensing mode for Gd3+ with detection limits of 39 and 53 nmol/L in HEPES buffer solution and saliva samples. The probe PT was successfully used for imaging of Gd3+ in L929 cells and zebrafish. Notably, the newly developed fluorescent peptide probe PT had extraordinary features such as highly water solubility, low biotoxicity and high specificity for Gd3+ in zebrafish and L929 cells, which showed great potential in the molecular diagnosis of the concentration of residual Gd3+ in human body.
As the most widely used magnetic resonance imaging contrast in clinical applications, gadolinium-based contrast agents play an important role in the clinical diagnosis and related research, while gadolinium deposition has been found to be closely related to nephrogenic systemic fibrosis and may cause multiple sclerosis, neurofibromatosis, inborn error of metabolism and other diseases. Therefore, the development of efficient assays for free Gd3+ is critical for the mechanistic study of these diseases. In this work, the fluorescent peptide probe PT consisted of (TPE-Glu-Glu-Glu-Pro-Gly-Glu-Glu-Glu) sequences was reported. The results showed that the efficient detection of Gd3+ in solution and biological fluids using the TPE-modified peptide probe PT without interferences of other metal ions was achieved. Meanwhile, the Job's analysis result indicated that the probe PT and Gd3+ formed a 1:3 complex and recovered its fluorescence, with a binding constant of 2.34×1015 L3/mol3. It was demonstrated that the fluorescent peptide probe PT provided a "Turn-On" sensing mode for Gd3+ with detection limits of 39 and 53 nmol/L in HEPES buffer solution and saliva samples. The probe PT was successfully used for imaging of Gd3+ in L929 cells and zebrafish. Notably, the newly developed fluorescent peptide probe PT had extraordinary features such as highly water solubility, low biotoxicity and high specificity for Gd3+ in zebrafish and L929 cells, which showed great potential in the molecular diagnosis of the concentration of residual Gd3+ in human body.
2022, 50(7): 1022-1031
doi: 10.19756/j.issn.0253-3820.210793
Abstract:
An ultrasensitive colorimetric sensor for detection of thrombin was designed based on loop mediated isothermal signal amplification (LAMP) triggered by aptamer sandwich-mediated enzymatic digestion. In the presence of thrombin, aptamer capable of recognizing thrombin heparin site and fibrinogen site was used to recognize thrombin and construct a sandwich structure. The Nb.BsrDI nicking endonuclease could recognize and cleave this complementary sequence to start-up loop mediated isothermal amplification. G-quadruplex-hemin DNAzyme could catalyze the oxidation of ABTS to ABTS·+ in the presence of H2O2, and the color changed to green. Under the optimal experimental conditions, the linear detection range of this method for thrombin was 0.01-1.0 ag/mL, the detection limit (3σ) was 0.008 ag/mL, and the regression equation was ΔA420 nm=0.187Cthrombin+0.171 (R2=0.991). When there were a large number of other interfering proteins in the serum sample, the sensor still had a high selectivity to thrombin. When this method was applied to the detection of thrombin content in serum samples, the recoveries were 96.1%-103.2%. This method innovatively integrated aptamer-based sandwich assay, loop-mediated isothermal amplification technology, and G-quadruplex-hemin DNAzyme enzymatic signal amplification technology that caused the ultrasensitive detection of thrombin. The method showed many advantages such as lower cost, simple operation and good stability, and could be used for highly sensitive clinical detection of thrombin in human serum.
An ultrasensitive colorimetric sensor for detection of thrombin was designed based on loop mediated isothermal signal amplification (LAMP) triggered by aptamer sandwich-mediated enzymatic digestion. In the presence of thrombin, aptamer capable of recognizing thrombin heparin site and fibrinogen site was used to recognize thrombin and construct a sandwich structure. The Nb.BsrDI nicking endonuclease could recognize and cleave this complementary sequence to start-up loop mediated isothermal amplification. G-quadruplex-hemin DNAzyme could catalyze the oxidation of ABTS to ABTS·+ in the presence of H2O2, and the color changed to green. Under the optimal experimental conditions, the linear detection range of this method for thrombin was 0.01-1.0 ag/mL, the detection limit (3σ) was 0.008 ag/mL, and the regression equation was ΔA420 nm=0.187Cthrombin+0.171 (R2=0.991). When there were a large number of other interfering proteins in the serum sample, the sensor still had a high selectivity to thrombin. When this method was applied to the detection of thrombin content in serum samples, the recoveries were 96.1%-103.2%. This method innovatively integrated aptamer-based sandwich assay, loop-mediated isothermal amplification technology, and G-quadruplex-hemin DNAzyme enzymatic signal amplification technology that caused the ultrasensitive detection of thrombin. The method showed many advantages such as lower cost, simple operation and good stability, and could be used for highly sensitive clinical detection of thrombin in human serum.
2022, 50(7): 1032-1040
doi: 10.19756/j.issn.0253-3820.210686
Abstract:
A fluorescence resonance energy transfer (FRET)-DNA nanomachine based on BHQ-2 and Cy5 was constructed for detection of prostate specific antigen (PSA). The introduction of fuel DNA would trigger the entropy increasing effect of the DNA nanomachine to cause the recycling of DNA nanomachine and release of more Cy5 signal probes, which further facilitated the cycling signal amplification for PSA analysis. The FRET-DNA nanomachine exhibited many advantages such as enzyme-free, low background, high sensitivity, high selectivity and easy operation. The DNA complementary hybridizations in working process of DNA nanomachine were characterized by agarose gel electrophoresis. Some important experimental parameters, such as the concentration and incubating time of fuel DNA, the concentration of PSA aptamer, were optimized. Under the optimized experimental conditions, the FRET-DNA nanomachine was employed to detect PSA protein with linearity ranging from 0.1 to 100 ng/mL and the limit of detection limit was 93.3 pg/mL (3σ). Comparing with commercial PSA kits based on enzyme-linked immunosorbent assay, this proposed strategy exhibited wider linearity rang and lower detection limit, which could be used to detect PSA in real serum samples. The easy operation and high reliability of this strategy showed potential quantitative power for future biomedical detection.
A fluorescence resonance energy transfer (FRET)-DNA nanomachine based on BHQ-2 and Cy5 was constructed for detection of prostate specific antigen (PSA). The introduction of fuel DNA would trigger the entropy increasing effect of the DNA nanomachine to cause the recycling of DNA nanomachine and release of more Cy5 signal probes, which further facilitated the cycling signal amplification for PSA analysis. The FRET-DNA nanomachine exhibited many advantages such as enzyme-free, low background, high sensitivity, high selectivity and easy operation. The DNA complementary hybridizations in working process of DNA nanomachine were characterized by agarose gel electrophoresis. Some important experimental parameters, such as the concentration and incubating time of fuel DNA, the concentration of PSA aptamer, were optimized. Under the optimized experimental conditions, the FRET-DNA nanomachine was employed to detect PSA protein with linearity ranging from 0.1 to 100 ng/mL and the limit of detection limit was 93.3 pg/mL (3σ). Comparing with commercial PSA kits based on enzyme-linked immunosorbent assay, this proposed strategy exhibited wider linearity rang and lower detection limit, which could be used to detect PSA in real serum samples. The easy operation and high reliability of this strategy showed potential quantitative power for future biomedical detection.
2022, 50(7): 1041-1047
doi: 10.19756/j.issn.0253-3820.221021
Abstract:
Foodborne pathogens are the main cause of seafood poisoning in the world, and the traditional electrochemical detection methods have always suffered from nonspecific adsorption and serious biological fouling in the practical complex samples. Therefore, it is urgent to develop antifouling and sensitive biosensor platforms for detecting foodborne pathogens in complex matrix. In this study, by integrating polyethylene glycol (PEG) with good hydrophilicity and chondroitin sulfate (CS) with excellent biocompatibility, an electrochemical DNA sensing interface for detection of the tlh gene segment of Vibrio parahaemolyticus based on synergistic antifouling of PEG and CS was constructed. Compared with sole poly(m-aminobenzoic acid) modified glassy carbon electrode (PABA/GCE), PEG/PABA/GCE and CS/PABA/GCE, CS/PEG/PABA/GCE exhibited many advantages such as excellent anti-protein (single protein and complex skim milk) adsorption performance and stability. Moreover, the sensing interface showed high sensitivity and satisfactory selectivity to the tlh gene segment in the range of 1.0×10-20-1.0×10-8 mol/L with a detection limit of 3.3×10-21 mol/L.
Foodborne pathogens are the main cause of seafood poisoning in the world, and the traditional electrochemical detection methods have always suffered from nonspecific adsorption and serious biological fouling in the practical complex samples. Therefore, it is urgent to develop antifouling and sensitive biosensor platforms for detecting foodborne pathogens in complex matrix. In this study, by integrating polyethylene glycol (PEG) with good hydrophilicity and chondroitin sulfate (CS) with excellent biocompatibility, an electrochemical DNA sensing interface for detection of the tlh gene segment of Vibrio parahaemolyticus based on synergistic antifouling of PEG and CS was constructed. Compared with sole poly(m-aminobenzoic acid) modified glassy carbon electrode (PABA/GCE), PEG/PABA/GCE and CS/PABA/GCE, CS/PEG/PABA/GCE exhibited many advantages such as excellent anti-protein (single protein and complex skim milk) adsorption performance and stability. Moreover, the sensing interface showed high sensitivity and satisfactory selectivity to the tlh gene segment in the range of 1.0×10-20-1.0×10-8 mol/L with a detection limit of 3.3×10-21 mol/L.
2022, 50(7): 1048-1056
doi: 10.19756/j.issn.0253-3820.221018
Abstract:
The identification and quantification of DNA adducts is an important technical issue in the research of DNA damage, epigenetics and genotoxic impurities screening. Various DNA hydrolysis methods with individual advantages are available for different applicable analytical purposes to produce bases, nucleosides or nucleic acid fragments. By taking the classic alkylation reagent mustard gas as a model compound, three common DNA hydrolysis methods including thermal hydrolysis, acid hydrolysis and enzymatic hydrolysis were comparatively used to pretreat the sample from in vitro incubation solution or in vivo animal exposure experiments. The produced DNA adducts were screened and quantitatively detected by mass spectrometry. Hydrolysis efficiency of DNA adducts in different analytical samples as well as different sites and adduct forms were investigated. Results showed that there were differences in the stability of DNA adducts derived from different base modification sites. The N-site adducts of guanine and adenine were relatively stable under each hydrolysis condition, while O6 site adducts of guanine were unstable to acid and thermal hydrolysis. In comparison, the efficiency of thermal hydrolysis was lower, while the acid hydrolysis was more efficient which improved 10.4%-94.9% hydrolysis yields and DNA-base adducts were more than 99% among the products, thus suitable for the quantitative analysis of structure-known DNA adducts by mass spectrometry. For enzymatic hydrolysis method, it could produce various adduct forms, such as base- and/or nucleoside-adducts, i.e., the product information was rich, which was suitable for screening and identification of structure-unknown adducts. However, the enzymatic hydrolysis efficiency was often affected by the factors such as DNA modification site, matrix effect and enzymatic hydrolysis conditions which might consequently affect the accuracy of DNA adduct quantification.
The identification and quantification of DNA adducts is an important technical issue in the research of DNA damage, epigenetics and genotoxic impurities screening. Various DNA hydrolysis methods with individual advantages are available for different applicable analytical purposes to produce bases, nucleosides or nucleic acid fragments. By taking the classic alkylation reagent mustard gas as a model compound, three common DNA hydrolysis methods including thermal hydrolysis, acid hydrolysis and enzymatic hydrolysis were comparatively used to pretreat the sample from in vitro incubation solution or in vivo animal exposure experiments. The produced DNA adducts were screened and quantitatively detected by mass spectrometry. Hydrolysis efficiency of DNA adducts in different analytical samples as well as different sites and adduct forms were investigated. Results showed that there were differences in the stability of DNA adducts derived from different base modification sites. The N-site adducts of guanine and adenine were relatively stable under each hydrolysis condition, while O6 site adducts of guanine were unstable to acid and thermal hydrolysis. In comparison, the efficiency of thermal hydrolysis was lower, while the acid hydrolysis was more efficient which improved 10.4%-94.9% hydrolysis yields and DNA-base adducts were more than 99% among the products, thus suitable for the quantitative analysis of structure-known DNA adducts by mass spectrometry. For enzymatic hydrolysis method, it could produce various adduct forms, such as base- and/or nucleoside-adducts, i.e., the product information was rich, which was suitable for screening and identification of structure-unknown adducts. However, the enzymatic hydrolysis efficiency was often affected by the factors such as DNA modification site, matrix effect and enzymatic hydrolysis conditions which might consequently affect the accuracy of DNA adduct quantification.
2022, 50(7): 1057-1064
doi: 10.19756/j.issn.0253-3820.221000
Abstract:
Volatile organic compounds can produce chemiluminescence on the surface of talc powder and refreshing powder. Under the optimal conditions, including reaction temperature of 210℃, detection wavelength of 425 nm and flow rate of carrier gas at 300 mL/min, there was a good linear relationship between the CTL signal intensity on talc surface and the concentration of n-propanal, and the slope (k) of linear regression equation could be used as the characteristic value for identification of talc powder. If n-propanal could not produce obvious CTL signal on the surface of some talc powder or could produce CTL signal but the k value was relatively close, then the CTL signals of six volatile organic compounds on the surface of talc powder were normalized and coded in sequence, and each talc powder corresponded to a digital coding, which could be used for identification of refreshing powder. The two methods abovementioned were successfully used for identification of 12 brands of refreshing powders. The k values of seven batches of the same refreshing powder were investigated, with RSD of 3.1%, showing excellent stability. Moreover, the method was verified to be fast and accurate by linear discriminant analysis.
Volatile organic compounds can produce chemiluminescence on the surface of talc powder and refreshing powder. Under the optimal conditions, including reaction temperature of 210℃, detection wavelength of 425 nm and flow rate of carrier gas at 300 mL/min, there was a good linear relationship between the CTL signal intensity on talc surface and the concentration of n-propanal, and the slope (k) of linear regression equation could be used as the characteristic value for identification of talc powder. If n-propanal could not produce obvious CTL signal on the surface of some talc powder or could produce CTL signal but the k value was relatively close, then the CTL signals of six volatile organic compounds on the surface of talc powder were normalized and coded in sequence, and each talc powder corresponded to a digital coding, which could be used for identification of refreshing powder. The two methods abovementioned were successfully used for identification of 12 brands of refreshing powders. The k values of seven batches of the same refreshing powder were investigated, with RSD of 3.1%, showing excellent stability. Moreover, the method was verified to be fast and accurate by linear discriminant analysis.
2022, 50(7): 1065-1071
doi: 10.19756/j.issn.0253-3820.210881
Abstract:
A biosensor for detection of myoglobin based on the technology of molecular bond rupture of piezoelectric quartz crystal excited by amplitude modulation resonant and the method of double aptamer sandwich were developed. The aptamer Ⅰ was coated onto the gold electrode surface of quartz crystal microbalance (QCM) through Au-S bond, and specifically bound to myoglobin, which coupled with aptamer Ⅱ-magnetic beads to enhance the mass response. When the peak-to-peak value of the excitation voltage was increased to 8 V at the resonant frequency for 50 MHz gold-plated quartz crystal, the layer of aptamer Ⅱ-magnetic beads bonded to the surface would be removed, resulting in the occurrence of molecular bond rupture process and the increase of the resonant frequency, and the QCM aptamer biosensor with high specificity for detection of myoglobin was developed. Under the optimized conditions, the linear range of detection of myoglobin was 1.0-500 ng/mL, and the detection limit (3σ) was 0.38 ng/mL. The recoveries of myoglobin in human serum sample ranged from 96.4% to 104.0%. Compared to traditional QCM sensing technology, the sensing method established here was simple, fast, and easy to operate. Besides, the aptamer biosensor based on molecular bond rupture technology had practical and market application value.
A biosensor for detection of myoglobin based on the technology of molecular bond rupture of piezoelectric quartz crystal excited by amplitude modulation resonant and the method of double aptamer sandwich were developed. The aptamer Ⅰ was coated onto the gold electrode surface of quartz crystal microbalance (QCM) through Au-S bond, and specifically bound to myoglobin, which coupled with aptamer Ⅱ-magnetic beads to enhance the mass response. When the peak-to-peak value of the excitation voltage was increased to 8 V at the resonant frequency for 50 MHz gold-plated quartz crystal, the layer of aptamer Ⅱ-magnetic beads bonded to the surface would be removed, resulting in the occurrence of molecular bond rupture process and the increase of the resonant frequency, and the QCM aptamer biosensor with high specificity for detection of myoglobin was developed. Under the optimized conditions, the linear range of detection of myoglobin was 1.0-500 ng/mL, and the detection limit (3σ) was 0.38 ng/mL. The recoveries of myoglobin in human serum sample ranged from 96.4% to 104.0%. Compared to traditional QCM sensing technology, the sensing method established here was simple, fast, and easy to operate. Besides, the aptamer biosensor based on molecular bond rupture technology had practical and market application value.
2022, 50(7): 1072-1082
doi: 10.19756/j.issn.0253-3820.221050
Abstract:
Cooking oil fumes are widely concerned because of the complex composition and the hard-to-degrade characterization. One of the most important pollutants in cooking oil fumes is formaldehyde which is a hazard to human health. In this study, a strain of Bacillus amyloliticus XF-1 screened out in previous work was used for efficiently degrading formaldehyde from the condensate of cooking oil fumes. The previous study found that when formaldehyde was the only carbon source, the biodegradation rate was reduced owing to the inhibition effect to the strain. It was necessary to investigate the metabolic mechanism of strain XF-1 and to illustrate the reason for growth inhibition. The metabolic profiling of XF-1 with different carbon sources and under different culture time conditions was analyzed by gas chromatography-time of flight-mass spectrometry (GC-TOF-MS). The results showed that different carbon sources caused different metabolic profiles of XF-1. The metabolic process was delayed using formaldehyde as the carbon source. The concentrations of cystine, aspartic acid and glutamine were significantly changed, which showed that the cell growth and proliferation were inhibited. This work provided a reference for improving the biodegradation efficiency of cooking oil fumes in the future.
Cooking oil fumes are widely concerned because of the complex composition and the hard-to-degrade characterization. One of the most important pollutants in cooking oil fumes is formaldehyde which is a hazard to human health. In this study, a strain of Bacillus amyloliticus XF-1 screened out in previous work was used for efficiently degrading formaldehyde from the condensate of cooking oil fumes. The previous study found that when formaldehyde was the only carbon source, the biodegradation rate was reduced owing to the inhibition effect to the strain. It was necessary to investigate the metabolic mechanism of strain XF-1 and to illustrate the reason for growth inhibition. The metabolic profiling of XF-1 with different carbon sources and under different culture time conditions was analyzed by gas chromatography-time of flight-mass spectrometry (GC-TOF-MS). The results showed that different carbon sources caused different metabolic profiles of XF-1. The metabolic process was delayed using formaldehyde as the carbon source. The concentrations of cystine, aspartic acid and glutamine were significantly changed, which showed that the cell growth and proliferation were inhibited. This work provided a reference for improving the biodegradation efficiency of cooking oil fumes in the future.
2022, 50(7): 1083-1092
doi: 10.19756/j.issn.0253-3820.211255
Abstract:
A targeted ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous determination of 32 kinds of amino acids in plasma from colorectal cancer (CRC) patients. The chromatographic separation was performed on an Agilent Zorbax SB-C18 column (150 mm×3.0 mm, 5 μm) with a binary gradient elution system (Mobile phase A:0.02% heptafluorobutyric acid and 0.2% formic acid in water; mobile phase B:methanol). The run time was 10 min. The multiple reaction monitoring mode was chosen with an electrospray ionization source operating in the positive ionization mode for data acquisition. The sample was pretreated based on protein precipitation. The average recoveries and matrix effects for 32 kinds of amino acids and 3 kinds of internal standards were 50.4%-182.4% and 41.0%-136.4%, respectively. The linear correlation coefficients were above 0.99 for 32 kinds amino acids. The intra- and inter-day accuracy for 32 kinds of amino acids ranged from -14.3% to 13.7% (RSD ≤ 8.8%) and from -14.4% to 13.4% (RSD ≤ 12.2%), respectively, and the deviations of stability under different conditions were within ±15%. This method was successfully utilized to quantify 32 kinds of amino acids in plasma samples from 6 CRC patients simultaneously.
A targeted ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous determination of 32 kinds of amino acids in plasma from colorectal cancer (CRC) patients. The chromatographic separation was performed on an Agilent Zorbax SB-C18 column (150 mm×3.0 mm, 5 μm) with a binary gradient elution system (Mobile phase A:0.02% heptafluorobutyric acid and 0.2% formic acid in water; mobile phase B:methanol). The run time was 10 min. The multiple reaction monitoring mode was chosen with an electrospray ionization source operating in the positive ionization mode for data acquisition. The sample was pretreated based on protein precipitation. The average recoveries and matrix effects for 32 kinds of amino acids and 3 kinds of internal standards were 50.4%-182.4% and 41.0%-136.4%, respectively. The linear correlation coefficients were above 0.99 for 32 kinds amino acids. The intra- and inter-day accuracy for 32 kinds of amino acids ranged from -14.3% to 13.7% (RSD ≤ 8.8%) and from -14.4% to 13.4% (RSD ≤ 12.2%), respectively, and the deviations of stability under different conditions were within ±15%. This method was successfully utilized to quantify 32 kinds of amino acids in plasma samples from 6 CRC patients simultaneously.
2022, 50(7): 1093-1102
doi: 10.19756/j.issn.0253-3820.210848
Abstract:
The amino functionalized magnetic nano adsorbent (MNPs-NH2) was prepared by solvothermal method for magnetic solid phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in aqueous medium in this work. The experimental results showed that the adsorbent could selectively adsorb high molecular weight PAHs with 4-6 benzene rings. The results of molecular simulation calculations and comparative experiments with other adsorbents showed that the amine groups on the surface of the adsorbents could not only promote the good dispersion of the adsorbent in water, but also enhance the adsorption of PAHs through hydrogen bonding. The MSPE-high performance liquid chromatography-fluorescence detection (HPLC-FLD) method for high molecular weight PAHs in water was established by optimizing various parameters affecting the extraction efficiency. In the linear range of 0.008-20 ng/mL, the recoveries of high molecular weight PAHs at two spiking concentration levels (1 ng/mL and 10 ng/mL) were 59.7%-99.0%, the relative standard deviations were 1.7%-9.0%, the limits of detection were 0.002-0.02 ng/mL, and the limits of quantification were 0.004-0.12 ng/mL. This method could be applied to the detection of high molecular weight PAHs in environmental water samples.
The amino functionalized magnetic nano adsorbent (MNPs-NH2) was prepared by solvothermal method for magnetic solid phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in aqueous medium in this work. The experimental results showed that the adsorbent could selectively adsorb high molecular weight PAHs with 4-6 benzene rings. The results of molecular simulation calculations and comparative experiments with other adsorbents showed that the amine groups on the surface of the adsorbents could not only promote the good dispersion of the adsorbent in water, but also enhance the adsorption of PAHs through hydrogen bonding. The MSPE-high performance liquid chromatography-fluorescence detection (HPLC-FLD) method for high molecular weight PAHs in water was established by optimizing various parameters affecting the extraction efficiency. In the linear range of 0.008-20 ng/mL, the recoveries of high molecular weight PAHs at two spiking concentration levels (1 ng/mL and 10 ng/mL) were 59.7%-99.0%, the relative standard deviations were 1.7%-9.0%, the limits of detection were 0.002-0.02 ng/mL, and the limits of quantification were 0.004-0.12 ng/mL. This method could be applied to the detection of high molecular weight PAHs in environmental water samples.
2022, 50(7): 1103-1111
doi: 10.19756/j.issn.0253-3820.221062
Abstract:
Bi2O3-TiO2 nanofibers (NFs) were synthesized by electrospinning method, and a geterojunction cataluminescence toluene gas sensor was thus designed by depositing Bi2O3-TiO2 NFs onto the cylindrical ceramic heating rod surface as cataluminescence material by dip-coating method. The crystalline phase and microstructure of Bi2O3-TiO2 NFs were displayed using X-ray diffraction and scanning electron microscope, and the cataluminescence mechanism and electrochemical characteristic of Bi2O3-TiO2 NFs in detection of toluene were analyzed by UV-Vis spectrometry, X-ray photoelectron spectroscopy and Fourier infrared spectroscopy (FT-IR). Density functional theory (DFT) was used to calculate the charge density and differential charge density of atoms in Bi2O3-TiO2 NFs heterojunction, and the sensitization mechanism of sensor was further proposed for detecting toluene gas. Under the optimal conditions including 450 nm of wavelength, 200 mL/min of flow rate and at 250℃, there was a good relationship between the CTL intensity of Bi30 toluene gas sensor and the toluene concentration in the range of 0.1-200 μg/m3. The detection limit was 0.1 μg/m3 (S/N=10), the RSD was 1.81%, and the dynamic response time and recover time of toluene gas sensor were 7.2 s and 9.4 s respectively. This study provided a feasible strategy for rapid and efficient detection of toluene, as well as a new sensing platform for detection of volatile organic compounds.
Bi2O3-TiO2 nanofibers (NFs) were synthesized by electrospinning method, and a geterojunction cataluminescence toluene gas sensor was thus designed by depositing Bi2O3-TiO2 NFs onto the cylindrical ceramic heating rod surface as cataluminescence material by dip-coating method. The crystalline phase and microstructure of Bi2O3-TiO2 NFs were displayed using X-ray diffraction and scanning electron microscope, and the cataluminescence mechanism and electrochemical characteristic of Bi2O3-TiO2 NFs in detection of toluene were analyzed by UV-Vis spectrometry, X-ray photoelectron spectroscopy and Fourier infrared spectroscopy (FT-IR). Density functional theory (DFT) was used to calculate the charge density and differential charge density of atoms in Bi2O3-TiO2 NFs heterojunction, and the sensitization mechanism of sensor was further proposed for detecting toluene gas. Under the optimal conditions including 450 nm of wavelength, 200 mL/min of flow rate and at 250℃, there was a good relationship between the CTL intensity of Bi30 toluene gas sensor and the toluene concentration in the range of 0.1-200 μg/m3. The detection limit was 0.1 μg/m3 (S/N=10), the RSD was 1.81%, and the dynamic response time and recover time of toluene gas sensor were 7.2 s and 9.4 s respectively. This study provided a feasible strategy for rapid and efficient detection of toluene, as well as a new sensing platform for detection of volatile organic compounds.
2022, 50(7): 1112-1121
doi: 10.19756/j.issn.0253-3820.201607
Abstract:
By using monolayer polystyrene colloidal spheres as the template, ZnO array-film was in-situ synthesized on the plate electrodes for gas sensors by template-assisted hydrothermal method. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) characterization results showed that the film was composed of ordered monolayer porous hollow spheres with pore size of about 4 nm. The gas-sensing performances of the prepared thin-film gas sensor were investigated. Under UV irradiation with a low optical radiation power (1.7 mW/cm2), the thin-film gas sensor based on ZnO monolayer hollow sphere array showed excellent NO2-sensing performances with a detection limit of 0.098 mg/m3, and the sensing response toward 2.45 mg/m3 NO2 gas could reach 5.7 with an ultra-fast response/recovery speed (3 s/5 s). With the finite difference time domain method, the local field intensity of the monolayer hollow sphere array-film was investigated, and it was found that the second-level response/recovery mechanism might be due to the relatively uniform local field intensity distribution of the monolayer hollow sphere array film.
By using monolayer polystyrene colloidal spheres as the template, ZnO array-film was in-situ synthesized on the plate electrodes for gas sensors by template-assisted hydrothermal method. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) characterization results showed that the film was composed of ordered monolayer porous hollow spheres with pore size of about 4 nm. The gas-sensing performances of the prepared thin-film gas sensor were investigated. Under UV irradiation with a low optical radiation power (1.7 mW/cm2), the thin-film gas sensor based on ZnO monolayer hollow sphere array showed excellent NO2-sensing performances with a detection limit of 0.098 mg/m3, and the sensing response toward 2.45 mg/m3 NO2 gas could reach 5.7 with an ultra-fast response/recovery speed (3 s/5 s). With the finite difference time domain method, the local field intensity of the monolayer hollow sphere array-film was investigated, and it was found that the second-level response/recovery mechanism might be due to the relatively uniform local field intensity distribution of the monolayer hollow sphere array film.
