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2020 Volume 48 Issue 9
2020, 48(9): 1121-1130
doi: 10.19756/j.issn.0253-3820.201111
Abstract:
C-reactive protein (CRP) is an important biomarker for acute inflammation and infection, and is widely used clinically for the assessment of various diseases and the monitoring of patients' conditions. At present, the clinical test methods for CRP mainly include immunoturbidimetry, enzyme-linked immunosorbent assays, and lateral flow assays. In recent years, the developments in analysis theory and improvements in materials science have resulted in the continual emergence of analytical methods and techniques, such as biosensor technology and microfluidics. Here, we summarized the development and application of CRP analytical methods and focused on the developments during the last five years. In addition, we predicted the research directions for novel CRP assays and provided new ideas for the development of CRP analytical methods with high sensitivity and specificity that could meet clinical needs.
C-reactive protein (CRP) is an important biomarker for acute inflammation and infection, and is widely used clinically for the assessment of various diseases and the monitoring of patients' conditions. At present, the clinical test methods for CRP mainly include immunoturbidimetry, enzyme-linked immunosorbent assays, and lateral flow assays. In recent years, the developments in analysis theory and improvements in materials science have resulted in the continual emergence of analytical methods and techniques, such as biosensor technology and microfluidics. Here, we summarized the development and application of CRP analytical methods and focused on the developments during the last five years. In addition, we predicted the research directions for novel CRP assays and provided new ideas for the development of CRP analytical methods with high sensitivity and specificity that could meet clinical needs.
2020, 48(9): 1131-1140
doi: 10.19756/j.issn.0253-3820.201034
Abstract:
Liquid electrode glow discharge has been developed and widely used in analytical chemistry due to its advantages such as small-size, low power-consumption, easy operation, high electron density and simple experimental setup. This review focused on the recent progresses on the application of the liquid electrode glow discharge microplasma in atomic spectroscopic analysis, including the perspective of liquid cathode glow discharge, liquid anode glow discharge and alternating current driven liquid electrode glow discharge optical emission spectrometry. The progress and application of liquid electrode glow discharge (LEGD) applied as the excitation source of atomic emission spectrum, the induction of chemical vapor generation and the combination with other chemical vapor generation were reviewed, and the development trends in the future was also prospected.
Liquid electrode glow discharge has been developed and widely used in analytical chemistry due to its advantages such as small-size, low power-consumption, easy operation, high electron density and simple experimental setup. This review focused on the recent progresses on the application of the liquid electrode glow discharge microplasma in atomic spectroscopic analysis, including the perspective of liquid cathode glow discharge, liquid anode glow discharge and alternating current driven liquid electrode glow discharge optical emission spectrometry. The progress and application of liquid electrode glow discharge (LEGD) applied as the excitation source of atomic emission spectrum, the induction of chemical vapor generation and the combination with other chemical vapor generation were reviewed, and the development trends in the future was also prospected.
2020, 48(9): 1141-1148
doi: 10.19756/j.issn.0253-3820.201249
Abstract:
Biofuel cell-based self-powered biosensor features with the advantages such as no extra power supplied, simple instrumentation, miniaturization and excellent anti-interference capability because the signal of which is directly proportional to the performance of the biofuel cell. However, the performance of self-powered biosensors needs to be improved because the biocatalysts of biofuel cells are easily deactivated. Herein, we developed a biofuel cell-based self-powered biosensor for the ultrasensitive heparin (Hep) detection via integration of the anion-exchange mechanism and molecular imprinting technology. In this case, molecular imprinting technology-based nanoporous gold acted as the bioanode and the potassium ferricyanide/polyimidazolium/reduced graphene oxide (Fe(CN)63-/Pim/rGO) complex played the role of the biocathode. In the absence of Hep, the biofuel cell-based self-powered biosensor could achieve a high open-circuit voltage and power density output. In the presence of Hep, Fe(CN)63- broke away from the Pim due to the stronger reaction between the Hep and Pim, which resulted in the electron acceptor decreased on the surface of the biocathode and further reduced the signal. Finally, the open-circuit voltage and power density output were reduced and the ultrasensitive Hep detection was realized via the change of the performance of biofuel cell. The detection limit was 0.01 pmol/L (S/N=3), being superior to the reported methods.
Biofuel cell-based self-powered biosensor features with the advantages such as no extra power supplied, simple instrumentation, miniaturization and excellent anti-interference capability because the signal of which is directly proportional to the performance of the biofuel cell. However, the performance of self-powered biosensors needs to be improved because the biocatalysts of biofuel cells are easily deactivated. Herein, we developed a biofuel cell-based self-powered biosensor for the ultrasensitive heparin (Hep) detection via integration of the anion-exchange mechanism and molecular imprinting technology. In this case, molecular imprinting technology-based nanoporous gold acted as the bioanode and the potassium ferricyanide/polyimidazolium/reduced graphene oxide (Fe(CN)63-/Pim/rGO) complex played the role of the biocathode. In the absence of Hep, the biofuel cell-based self-powered biosensor could achieve a high open-circuit voltage and power density output. In the presence of Hep, Fe(CN)63- broke away from the Pim due to the stronger reaction between the Hep and Pim, which resulted in the electron acceptor decreased on the surface of the biocathode and further reduced the signal. Finally, the open-circuit voltage and power density output were reduced and the ultrasensitive Hep detection was realized via the change of the performance of biofuel cell. The detection limit was 0.01 pmol/L (S/N=3), being superior to the reported methods.
2020, 48(9): 1149-1159
doi: 10.19756/j.issn.0253-3820.201019
Abstract:
A flexible graphene platform electrode (GPE) was prepared by transferring chemical vapor deposition graphene film from Cu foil to polyethylene terephthalate substrate with the help of polymethyl-methacrylate. L-Arginine (L-Arg) was electrodeposited on GPE to form poly(L-Arg)/GPE (P(L-Arg)/GPE) which was then characterized by scanning electron microscopy, energy dispersive spectroscopy and Raman spectroscopy. The electrocatalytic activity and enhanced conductivity of P(L-Arg)/GPE sensor was evaluated by determining xanthine (XA) in the presence of uric acid (UA) and hypoxanthine (HX) in phosphate buffer solution (PBS). The electrochemical behaviours of XA on P(L-Arg)/GPE were studied by cyclic voltammetry and differential pulse voltammetry in comparison with those on bare GPE. Further, the proposed sensor was used not only to achieve the selective determination of XA, but also to separate the voltammetric signals of UA-XA and XA-HX with potential differences of 420 and 384 mV, respectively. Under the optimized conditions, the proposed sensor displayed superb sensing property towards XA with a wide linear range from 0.5 μmol/L to 140 μmol/L, along with a detection limit of 0.08 μmol/L (S/N=3). The P(L-Arg)/GPE was successfully applied to determine XA in human serum with good stability, reproducibility, high sensitivity, low cost as well as high resistance to interferences.
A flexible graphene platform electrode (GPE) was prepared by transferring chemical vapor deposition graphene film from Cu foil to polyethylene terephthalate substrate with the help of polymethyl-methacrylate. L-Arginine (L-Arg) was electrodeposited on GPE to form poly(L-Arg)/GPE (P(L-Arg)/GPE) which was then characterized by scanning electron microscopy, energy dispersive spectroscopy and Raman spectroscopy. The electrocatalytic activity and enhanced conductivity of P(L-Arg)/GPE sensor was evaluated by determining xanthine (XA) in the presence of uric acid (UA) and hypoxanthine (HX) in phosphate buffer solution (PBS). The electrochemical behaviours of XA on P(L-Arg)/GPE were studied by cyclic voltammetry and differential pulse voltammetry in comparison with those on bare GPE. Further, the proposed sensor was used not only to achieve the selective determination of XA, but also to separate the voltammetric signals of UA-XA and XA-HX with potential differences of 420 and 384 mV, respectively. Under the optimized conditions, the proposed sensor displayed superb sensing property towards XA with a wide linear range from 0.5 μmol/L to 140 μmol/L, along with a detection limit of 0.08 μmol/L (S/N=3). The P(L-Arg)/GPE was successfully applied to determine XA in human serum with good stability, reproducibility, high sensitivity, low cost as well as high resistance to interferences.
2020, 48(9): 1160-1168
doi: 10.19756/j.issn.0253-3820.191579
Abstract:
Histopathology and serum biochemical indicators (urea nitrogen and creatinine) were investigated to evaluate the kidney injury caused by the combination use of isoniazid (100 mg/kg/d, ig)) and rifampicin (100 mg/(kg·d, ig)), which were used as anti-tuberculous drug. The endogenous metabolites extracted from kidney tissue were evaluated based on gas chromatography-mass spectrometry coupled with partial least squares-discriminant analysis and other multidimensional as well as unidimensional statistical methods. Glutathione, which was reported to protect tissue from damage caused by anti-tuberculosis drugs, was used to treat rats(250 mg/(kg·d, iv)) with kidney damage. Biochemical indicators showed that creatinine and urea nitrogen increased (p<0.05) greatly after intragastrically administrated with isoniazid and rifampicin. In kidney, 31 endogenous metabolites were identified as potential biomarkers, including tyrosine, proline, uridine and palmitoleic acid, etc. All these results suggested that the combination use of isoniazid and rifampicin caused serious damage to kidney and disturbed the fatty acid metabolism, arginine and proline metabolism. In addition, glutathione reduced the level of serum urea nitrogen (p<0.05) obviously and alleviated proliferation of glomerular mesangium. These results indicated that glutathione had good therapeutic effects on kidney injury caused by antituberculous drug and significantly regulated the abundance of palmitoleic acid, 4-hydrobutyric acid, citrulline, gluconolactone, guanidinoacetic acid and piperidine acid in kidney.
Histopathology and serum biochemical indicators (urea nitrogen and creatinine) were investigated to evaluate the kidney injury caused by the combination use of isoniazid (100 mg/kg/d, ig)) and rifampicin (100 mg/(kg·d, ig)), which were used as anti-tuberculous drug. The endogenous metabolites extracted from kidney tissue were evaluated based on gas chromatography-mass spectrometry coupled with partial least squares-discriminant analysis and other multidimensional as well as unidimensional statistical methods. Glutathione, which was reported to protect tissue from damage caused by anti-tuberculosis drugs, was used to treat rats(250 mg/(kg·d, iv)) with kidney damage. Biochemical indicators showed that creatinine and urea nitrogen increased (p<0.05) greatly after intragastrically administrated with isoniazid and rifampicin. In kidney, 31 endogenous metabolites were identified as potential biomarkers, including tyrosine, proline, uridine and palmitoleic acid, etc. All these results suggested that the combination use of isoniazid and rifampicin caused serious damage to kidney and disturbed the fatty acid metabolism, arginine and proline metabolism. In addition, glutathione reduced the level of serum urea nitrogen (p<0.05) obviously and alleviated proliferation of glomerular mesangium. These results indicated that glutathione had good therapeutic effects on kidney injury caused by antituberculous drug and significantly regulated the abundance of palmitoleic acid, 4-hydrobutyric acid, citrulline, gluconolactone, guanidinoacetic acid and piperidine acid in kidney.
2020, 48(9): 1169-1176
doi: 10.19756/j.issn.0253-3820.201181
Abstract:
A novel photoelectrochemical analytical method for ultrasensitive determination of ubiquinone 10 (UQ10) was established by using electrodeposited ZnO nanorods modified indium tin oxide electrode (ZnONR/ITO) as the first working electrode and glassy carbon electrode (GCE) as second working electrode. UQ10 was reduced to UQ10H2 on GCE, which was acted as electron donor with following oxidation on ZnONR/ITO with reduced photocurrent for UQ10 determination. The conditions for electrodeposited ZnONR and photoelectrochemical detection were optimized. Under the optimal conditions, the photocurrent were proportional to the logarithm of the UQ10 concentration in the range of 1.0×10-12-1.0×10-5 mol/L with a detection limits of 3.3×10-13 mol/L (S/N=3).
A novel photoelectrochemical analytical method for ultrasensitive determination of ubiquinone 10 (UQ10) was established by using electrodeposited ZnO nanorods modified indium tin oxide electrode (ZnONR/ITO) as the first working electrode and glassy carbon electrode (GCE) as second working electrode. UQ10 was reduced to UQ10H2 on GCE, which was acted as electron donor with following oxidation on ZnONR/ITO with reduced photocurrent for UQ10 determination. The conditions for electrodeposited ZnONR and photoelectrochemical detection were optimized. Under the optimal conditions, the photocurrent were proportional to the logarithm of the UQ10 concentration in the range of 1.0×10-12-1.0×10-5 mol/L with a detection limits of 3.3×10-13 mol/L (S/N=3).
2020, 48(9): 1177-1184
doi: 10.19756/j.issn.0253-3820.201241
Abstract:
Palladium-zinc oxide (Pd-ZnO) hollow nanotubes were prepared by using PdCl2 and Zn(Ac)2 as raw material through electrospinning technique combined with high temperature calcination. The presence of Pd improved the distribution of ZnO. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction characterization confirmed the formation of the Pd-ZnO hollow nanofiber with an inner diameter of 240 nm. Pd nanoparticles (PdNPs) with the size of 80 nm were distributed uniformly on the nanotubes. X-ray photoelectron spectroscopy proved that PdNPs mainly existed in the form of PdO. The obtained Pd-ZnO modified glassy carbon electrode exhibited excellent catalytic activity for the oxidation of dopamine (DA), ascorbic acid (AA) and uric acid (UA). Differential pulse voltammetry was successfully applied for the simultaneous measurement of DA, AA and UA without mutual interference. The linear concentration ranges of DA, AA and UA were 3.0×10-7 -3.0×10-5 mol/L (R2=0.9967), 1.0×10-5 -1.0×10-3 mol/L (R2=0.9991) and 6.0×10-6 -6.0×10-4 mol/L (R2=0.9935), with the corresponding detection limits (S/N=3) of 1.0×10-8 mol/L, 1.0×10-6 mol/L and 3.0×10-6 mol/L, respectively. The Pd-ZnO electrode with good reproducibility and stability was applicable for the simultaneous measurement of DA, AA and UA.
Palladium-zinc oxide (Pd-ZnO) hollow nanotubes were prepared by using PdCl2 and Zn(Ac)2 as raw material through electrospinning technique combined with high temperature calcination. The presence of Pd improved the distribution of ZnO. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction characterization confirmed the formation of the Pd-ZnO hollow nanofiber with an inner diameter of 240 nm. Pd nanoparticles (PdNPs) with the size of 80 nm were distributed uniformly on the nanotubes. X-ray photoelectron spectroscopy proved that PdNPs mainly existed in the form of PdO. The obtained Pd-ZnO modified glassy carbon electrode exhibited excellent catalytic activity for the oxidation of dopamine (DA), ascorbic acid (AA) and uric acid (UA). Differential pulse voltammetry was successfully applied for the simultaneous measurement of DA, AA and UA without mutual interference. The linear concentration ranges of DA, AA and UA were 3.0×10-7 -3.0×10-5 mol/L (R2=0.9967), 1.0×10-5 -1.0×10-3 mol/L (R2=0.9991) and 6.0×10-6 -6.0×10-4 mol/L (R2=0.9935), with the corresponding detection limits (S/N=3) of 1.0×10-8 mol/L, 1.0×10-6 mol/L and 3.0×10-6 mol/L, respectively. The Pd-ZnO electrode with good reproducibility and stability was applicable for the simultaneous measurement of DA, AA and UA.
2020, 48(9): 1185-1192
doi: 10.19756/j.issn.0253-3820.201222
Abstract:
MicroRNA-141 (miRNA-141) is of great significance in the early diagnosis and treatment of related cancers. Here, a biosensor was developed for detection of miRNA-141. Firstly, bio-metal organic framework (bio-MOF) with a certain porosity and good biocompatibility was synthesized. The bio-MOF could encapsulate a large number of methylene blue (MB) via ion-exchange process and maintain the biological activity of MB. Secondly, as one of the target recycling signal amplification technologies, catalyzed hairpin assembly (CHA) could assist the target miRNA-141 cycle to achieve signal amplification and further improve the biosensor sensitivity. As a result, the proposed ECL biosensor exhibited good sensitivity for microRNA-141 detection in a linear range from 1.0×10-16 mol/L to 1.0×10-6 mol/L with a limit of detection (LOD) of 3.3×10-17 mol/L (S/N=3). The spiked recoveries ranged from 99.9% to 102.0% (RSD ≤ 2.1%). The biosensor showed good stability and selectivity, wide linear range and high sensitivity, and opened up a new avenue for highly sensitive detection of various miRNAs.
MicroRNA-141 (miRNA-141) is of great significance in the early diagnosis and treatment of related cancers. Here, a biosensor was developed for detection of miRNA-141. Firstly, bio-metal organic framework (bio-MOF) with a certain porosity and good biocompatibility was synthesized. The bio-MOF could encapsulate a large number of methylene blue (MB) via ion-exchange process and maintain the biological activity of MB. Secondly, as one of the target recycling signal amplification technologies, catalyzed hairpin assembly (CHA) could assist the target miRNA-141 cycle to achieve signal amplification and further improve the biosensor sensitivity. As a result, the proposed ECL biosensor exhibited good sensitivity for microRNA-141 detection in a linear range from 1.0×10-16 mol/L to 1.0×10-6 mol/L with a limit of detection (LOD) of 3.3×10-17 mol/L (S/N=3). The spiked recoveries ranged from 99.9% to 102.0% (RSD ≤ 2.1%). The biosensor showed good stability and selectivity, wide linear range and high sensitivity, and opened up a new avenue for highly sensitive detection of various miRNAs.
2020, 48(9): 1193-1201
doi: 10.19756/j.issn.0253-3820.201144
Abstract:
MicroRNAs (miRNAs) are biomarkers and potential therapeutic targets for various diseases. It is important to develop convenient and sensitive methods for miRNAs analysis. Herein, by integrating the high signal amplification capability of hybridization chain reaction (HCR) and the excellent luminescence performance of DNA-templated silver nanoclusters (DNA-AgNCs), a versatile and label-free fluorescent sensor was constructed for highly sensitive miRNA-21 detection. First of all, the DNA template for synthesizing AgNCs was blocked in the hairpin DNA for HCR assembly. Addition of the target DNA could trigger self-assembly of hairpin DNAs, and release numerous free DNA template for the synthesis of near-infrared fluorescent AgNCs. The fluorescence intensity of AgNCs was positively correlated with concentration of trigger DNA. Furthermore, by introducing an auxiliary hairpin containing a blocked HCR initiator sequence, the HCR-AgNCs system could be adapted as a universal sensing platform for target detection. Taking miRNA-21 analysis as an example, in the presence of miRNA-21, the auxiliary hairpin could be opened, releasing the free trigger DNA sequence for HCR, which in turn initiated the HCR reaction and the following synthesis of AgNCs. The results showed that the linear range of this method for miRNA-21 detection was from 250 pmol/L to 8 nmol/L, and the detection limit was as low as 19.9 pmol/L (3σ/S). The HCR-AgNCs system was label-free, sensitive and extendable, which could be used as a universal sensing platform for analyzing different types of targets. This approach may provide a practical method for clinical diagnosis of biomarkers.
MicroRNAs (miRNAs) are biomarkers and potential therapeutic targets for various diseases. It is important to develop convenient and sensitive methods for miRNAs analysis. Herein, by integrating the high signal amplification capability of hybridization chain reaction (HCR) and the excellent luminescence performance of DNA-templated silver nanoclusters (DNA-AgNCs), a versatile and label-free fluorescent sensor was constructed for highly sensitive miRNA-21 detection. First of all, the DNA template for synthesizing AgNCs was blocked in the hairpin DNA for HCR assembly. Addition of the target DNA could trigger self-assembly of hairpin DNAs, and release numerous free DNA template for the synthesis of near-infrared fluorescent AgNCs. The fluorescence intensity of AgNCs was positively correlated with concentration of trigger DNA. Furthermore, by introducing an auxiliary hairpin containing a blocked HCR initiator sequence, the HCR-AgNCs system could be adapted as a universal sensing platform for target detection. Taking miRNA-21 analysis as an example, in the presence of miRNA-21, the auxiliary hairpin could be opened, releasing the free trigger DNA sequence for HCR, which in turn initiated the HCR reaction and the following synthesis of AgNCs. The results showed that the linear range of this method for miRNA-21 detection was from 250 pmol/L to 8 nmol/L, and the detection limit was as low as 19.9 pmol/L (3σ/S). The HCR-AgNCs system was label-free, sensitive and extendable, which could be used as a universal sensing platform for analyzing different types of targets. This approach may provide a practical method for clinical diagnosis of biomarkers.
2020, 48(9): 1202-1209
doi: 10.19756/j.issn.0253-3820.191634
Abstract:
Nitrate, nitrite and ammonia nitrogen (3-Nitrogen) are the main pollutants in water. "3-Nitrogen" pollution appears in both surface water and shallow groundwater in China. In this study, we combined the chromogenic method with the microfluidic technology to prepare the chip for simultaneous detection of "3-Nitrogen". Firstly, single-channel paper-based microfluidic chips were fabricated to verify the validity of the detection methods for three nitrogen-containing compounds and to optimize the reaction conditions. The corresponding detection limits were calculated to be 0.001 mmol/L, 1 mmol/L and 1 mg/L, respectively. In the testing of the actual samples, the spiked recoveries of the three samples were 95.4%-114.9%. Secondly, through a reasonable structural design, the single-channel paper-based microfluidic chips for the detection of three nitrogen-containing compounds were integrated into a multi-channel paper-based microfluidic chip for simultaneous detection of "3-Nitrogen". The detection results obtained by the multi-channel paper-based microfluidic chip maintained good consistency with those of the single-channel paper-based microfluidic chip. The multi-channel paper-based microfluidic chip based on chromogenic method proposed here could simultaneously detect "3-Nitrogen" in water, and the chip had the characteristics of low cost, high sensitivity and easy operation, as well as rapid detection. The technology showed great potential in detection of pollutants in water-contaminated areas with limited resources.
Nitrate, nitrite and ammonia nitrogen (3-Nitrogen) are the main pollutants in water. "3-Nitrogen" pollution appears in both surface water and shallow groundwater in China. In this study, we combined the chromogenic method with the microfluidic technology to prepare the chip for simultaneous detection of "3-Nitrogen". Firstly, single-channel paper-based microfluidic chips were fabricated to verify the validity of the detection methods for three nitrogen-containing compounds and to optimize the reaction conditions. The corresponding detection limits were calculated to be 0.001 mmol/L, 1 mmol/L and 1 mg/L, respectively. In the testing of the actual samples, the spiked recoveries of the three samples were 95.4%-114.9%. Secondly, through a reasonable structural design, the single-channel paper-based microfluidic chips for the detection of three nitrogen-containing compounds were integrated into a multi-channel paper-based microfluidic chip for simultaneous detection of "3-Nitrogen". The detection results obtained by the multi-channel paper-based microfluidic chip maintained good consistency with those of the single-channel paper-based microfluidic chip. The multi-channel paper-based microfluidic chip based on chromogenic method proposed here could simultaneously detect "3-Nitrogen" in water, and the chip had the characteristics of low cost, high sensitivity and easy operation, as well as rapid detection. The technology showed great potential in detection of pollutants in water-contaminated areas with limited resources.
2020, 48(9): 1210-1218
doi: 10.19756/j.issn.0253-3820.191462
Abstract:
The qualitative and quantitative analysis of the effective components is one of the focus of drug analysis. Normally, during routine measurement, sample pretreatment is always necessary to decrease or eliminate the interference of complex drug excipients, which is time-consuming and hard to handle. Therefore, it is highly demanded to develop rapid screening techniques towards high qualification and high efficiency for drug analysis. In this work, by using the bifonazole medicine as the model target, the rapid qualitative analysis of effective components was realized with the combination of Raman spectroscopy and chemmometric techniques including principal component analysis (PCA) and support vector machine (SVM). To exclude the unavoidable random interference from the complex composition of drug excipients to the qualitative analysis of target with low concentration (1%), the PCA method was used to precisely locate and extract the characteristic Raman signal of bifonazole. Furthermore, PCA combined with SVM classifier was applied to extract the tiny difference of Raman spectra, especially the two peaks at 1600 cm-1 and 1650 cm-1, from different manufactories. The result showed that the strategy could successfully distinguish and identify commercial drugs from different manufactories. This research implies that Raman spectroscopy is a very promising nondestructive and fast traceability analysis technique for drug analysis.
The qualitative and quantitative analysis of the effective components is one of the focus of drug analysis. Normally, during routine measurement, sample pretreatment is always necessary to decrease or eliminate the interference of complex drug excipients, which is time-consuming and hard to handle. Therefore, it is highly demanded to develop rapid screening techniques towards high qualification and high efficiency for drug analysis. In this work, by using the bifonazole medicine as the model target, the rapid qualitative analysis of effective components was realized with the combination of Raman spectroscopy and chemmometric techniques including principal component analysis (PCA) and support vector machine (SVM). To exclude the unavoidable random interference from the complex composition of drug excipients to the qualitative analysis of target with low concentration (1%), the PCA method was used to precisely locate and extract the characteristic Raman signal of bifonazole. Furthermore, PCA combined with SVM classifier was applied to extract the tiny difference of Raman spectra, especially the two peaks at 1600 cm-1 and 1650 cm-1, from different manufactories. The result showed that the strategy could successfully distinguish and identify commercial drugs from different manufactories. This research implies that Raman spectroscopy is a very promising nondestructive and fast traceability analysis technique for drug analysis.
2020, 48(9): 1219-1227
doi: 10.19756/j.issn.0253-3820.201171
Abstract:
Nano-drugs with dual advantages of targeted drug delivery and controllable release have become a new research hotspot of anti-tumor drugs. In the application of nano-drugs, the evaluation of drug efficacy is a very important issue. Herein, nanoindentation based on atomic force microscopy was used to analyze the changes in the mechanical properties of cells (Young's modulus and viscoelasticity, etc.) co-incubated with nano-drugs to measure the drug efficacy. The effect of doxorubicin (DOX) and camptothecin (CPT) in liposomes on cervical cancer (HeLa) cells was more significant than that of free DOX. Furthermore, the difference in the efficacy of liposomes mixed with DOX and CPT at different molar ratios (4:1 and 1:4) on HeLa cells were detected, and it was found that the synergistic effect of the two drugs enhanced the efficacy at 4:1 molar ratio. Finally, the viscoelasticity of HeLa cells co-incubated with nano-drugs was evaluated, and it was found that the viscoelasticity of the cells decreased with the extension of the co-incubation time of nano-drugs. This study provided a simple and effective method for screening nano-drugs.
Nano-drugs with dual advantages of targeted drug delivery and controllable release have become a new research hotspot of anti-tumor drugs. In the application of nano-drugs, the evaluation of drug efficacy is a very important issue. Herein, nanoindentation based on atomic force microscopy was used to analyze the changes in the mechanical properties of cells (Young's modulus and viscoelasticity, etc.) co-incubated with nano-drugs to measure the drug efficacy. The effect of doxorubicin (DOX) and camptothecin (CPT) in liposomes on cervical cancer (HeLa) cells was more significant than that of free DOX. Furthermore, the difference in the efficacy of liposomes mixed with DOX and CPT at different molar ratios (4:1 and 1:4) on HeLa cells were detected, and it was found that the synergistic effect of the two drugs enhanced the efficacy at 4:1 molar ratio. Finally, the viscoelasticity of HeLa cells co-incubated with nano-drugs was evaluated, and it was found that the viscoelasticity of the cells decreased with the extension of the co-incubation time of nano-drugs. This study provided a simple and effective method for screening nano-drugs.
2020, 48(9): 1228-1235
doi: 10.19756/j.issn.0253-3820.191560
Abstract:
A non-target screening analytical method for volatile organic compounds (VOCs) in drinking water by headspace-solid phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) was established. The operating parameters of HS-SPME were optimized by the number of peaks and peak area of the extract. The optimum working conditions of four different extracted fibers (100 μm PDMS, 65 μm PDMS/DVB, 85 μm PA and 75 μm CAR/PDMS) were investigated, including incubation time, extraction time, extraction temperature, NaCl concentration and desorption time. Comparing the species extracted by the four fibers with the oil-water partition ratio coefficient, it was found that the number of substances extracted by 100 μm PDMS was the least, and the extracted substances overlaped was repeated with other fibers. Therefore, it could be replaced by the three other extraction fibers. The three kinds of extracted fibers were selected for non-target screening of two kinds of tap water samples in Wuhan (the source water came from the Yangtze river and the Hanjiang river), and the substances with matching degree greater than 70% were selected for analysis. The results showed that 35 substances were identified from the tap water samples from the Han River, and 34 substances were identified from the tap water samples from the Yangtze River. The two had 18 common substances. By comparing the types of substances screened in the two water samples, it was found that the esters were the most abundant substances, followed by the aldehydes and phenols. Organic solvents was not used in the whole process, and the pollution caused by the solvent could avoided. The method was friendly to the environment, and could be used for screening and analysis of VOCs in tap water.
A non-target screening analytical method for volatile organic compounds (VOCs) in drinking water by headspace-solid phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) was established. The operating parameters of HS-SPME were optimized by the number of peaks and peak area of the extract. The optimum working conditions of four different extracted fibers (100 μm PDMS, 65 μm PDMS/DVB, 85 μm PA and 75 μm CAR/PDMS) were investigated, including incubation time, extraction time, extraction temperature, NaCl concentration and desorption time. Comparing the species extracted by the four fibers with the oil-water partition ratio coefficient, it was found that the number of substances extracted by 100 μm PDMS was the least, and the extracted substances overlaped was repeated with other fibers. Therefore, it could be replaced by the three other extraction fibers. The three kinds of extracted fibers were selected for non-target screening of two kinds of tap water samples in Wuhan (the source water came from the Yangtze river and the Hanjiang river), and the substances with matching degree greater than 70% were selected for analysis. The results showed that 35 substances were identified from the tap water samples from the Han River, and 34 substances were identified from the tap water samples from the Yangtze River. The two had 18 common substances. By comparing the types of substances screened in the two water samples, it was found that the esters were the most abundant substances, followed by the aldehydes and phenols. Organic solvents was not used in the whole process, and the pollution caused by the solvent could avoided. The method was friendly to the environment, and could be used for screening and analysis of VOCs in tap water.
2020, 48(9): 1236-1243
doi: 10.19756/j.issn.0253-3820.191725
Abstract:
The ambient mass spectrometry (MS) profiles of Stephania tetrandra and its toxic adulteration, Aristolochia fangchi, were obtained by using direct spray mass spectrometry. The MS behaviors of tetrandrine and fangchinoline in Stephania tetrandra, aristolochic acid A and magnoflorine in Aristolochia fangchi were studied. A simple and rapid method for distinguishing Stephania tetrandra from Aristolochia fangchi was established by analyzing their ambient MS profiles. The results showed that under the positive ion mode, Stephania tetrandra and Aristolochia fangchi could be identified easily and effectively according to their symbolic components, fangchinoline and tetrandrine in Stephania tetrandra. The method was simple, fast, effective, with no need of sample pretreatment, which was helpful for the quality control of fangchi herbal medicine. At the same time, the study on the electrospray behavior of aristolochic acid A has certain reference significance for the ambient MS analysis of aristolochic acid A.
The ambient mass spectrometry (MS) profiles of Stephania tetrandra and its toxic adulteration, Aristolochia fangchi, were obtained by using direct spray mass spectrometry. The MS behaviors of tetrandrine and fangchinoline in Stephania tetrandra, aristolochic acid A and magnoflorine in Aristolochia fangchi were studied. A simple and rapid method for distinguishing Stephania tetrandra from Aristolochia fangchi was established by analyzing their ambient MS profiles. The results showed that under the positive ion mode, Stephania tetrandra and Aristolochia fangchi could be identified easily and effectively according to their symbolic components, fangchinoline and tetrandrine in Stephania tetrandra. The method was simple, fast, effective, with no need of sample pretreatment, which was helpful for the quality control of fangchi herbal medicine. At the same time, the study on the electrospray behavior of aristolochic acid A has certain reference significance for the ambient MS analysis of aristolochic acid A.
2020, 48(9): 1244-1251
doi: 10.19756/j.issn.0253-3820.201140
Abstract:
Breakable capsule for cigarette filter was analyzed by near-infrared spectroscopy (NIRS) and gas chromatography-mass spectrometry (GC/MS), respectively. A total of twenty-seven different batches of three types of breakable capsules, including fresh sweet, honey sweet and peppermint, were investigated and their near-infrared spectra were collected. Classification model of three types of breakable capsule was established by the soft independent modeling of class analogy (SIMCA) with near-infrared spectra. Linear discriminant analysis (LDA) was used to evaluate the consistency of breakable capsule of the same type and different batches. Simultaneously, main volatile and semi-volatile components in the three types of breakable capsules were analyzed by GC/MS. The results showed that the main volatile and semi-volatile components of breakable capsules were different with different flavor types. NIRS could effectively identify the breakable capsule with different color wall materials. The established SIMCA model could successfully separate three types of breakable capsules, and the classifying accuracy of fresh sweet, honey sweet and peppermint breakable capsules was above 90%. At the same time, LDA models could separate different batches within each type of breakable capsule very well. NIRS was simple to operate and provided a novel, rapid, high-accuracy and nondestructive method for analysis of different types of breakable capsules.
Breakable capsule for cigarette filter was analyzed by near-infrared spectroscopy (NIRS) and gas chromatography-mass spectrometry (GC/MS), respectively. A total of twenty-seven different batches of three types of breakable capsules, including fresh sweet, honey sweet and peppermint, were investigated and their near-infrared spectra were collected. Classification model of three types of breakable capsule was established by the soft independent modeling of class analogy (SIMCA) with near-infrared spectra. Linear discriminant analysis (LDA) was used to evaluate the consistency of breakable capsule of the same type and different batches. Simultaneously, main volatile and semi-volatile components in the three types of breakable capsules were analyzed by GC/MS. The results showed that the main volatile and semi-volatile components of breakable capsules were different with different flavor types. NIRS could effectively identify the breakable capsule with different color wall materials. The established SIMCA model could successfully separate three types of breakable capsules, and the classifying accuracy of fresh sweet, honey sweet and peppermint breakable capsules was above 90%. At the same time, LDA models could separate different batches within each type of breakable capsule very well. NIRS was simple to operate and provided a novel, rapid, high-accuracy and nondestructive method for analysis of different types of breakable capsules.
2020, 48(9): 1252-1259
doi: 10.19756/j.issn.0253-3820.191665
Abstract:
Tea contains a variety of functional active substances such as γ-aminobutyric acid (GABA), which plays a good role in health care. Rapid identification of active components such as γ-aminobutyric acid in tea is conducive to improving the effective utilization of tea resources. In this work, qualitative and quantitative analysis of γ-aminobutyric acid in tea by direct analysis in real time (DART) ionization source coupled with triple quadrupole mass spectrometry was developed. The content of γ-aminobutyric acid in 10 kinds of tea samples was determined by this method. The results showed that the content of GABA in different tea samples were different, among which Jiuxiang green bud tea had the highest GABA content (227.2 μg/g), followed by Xinyang Maojian tea (161.2 μg/g), and Rizhao green tea had the lowest GABA content (75.6 μg/g). The test results are in good agreement with the results of the 2,4-dinitrofluorobenzene pre-column HPLC method. This method is simple and efficient, which can provide an effective method for rapidly screening tea varieties with high content of GABA. DART-MS method also has broad application in the fields of food active substance analysis, environmental organic pollutants, early screening of metabolic diseases and other fields.
Tea contains a variety of functional active substances such as γ-aminobutyric acid (GABA), which plays a good role in health care. Rapid identification of active components such as γ-aminobutyric acid in tea is conducive to improving the effective utilization of tea resources. In this work, qualitative and quantitative analysis of γ-aminobutyric acid in tea by direct analysis in real time (DART) ionization source coupled with triple quadrupole mass spectrometry was developed. The content of γ-aminobutyric acid in 10 kinds of tea samples was determined by this method. The results showed that the content of GABA in different tea samples were different, among which Jiuxiang green bud tea had the highest GABA content (227.2 μg/g), followed by Xinyang Maojian tea (161.2 μg/g), and Rizhao green tea had the lowest GABA content (75.6 μg/g). The test results are in good agreement with the results of the 2,4-dinitrofluorobenzene pre-column HPLC method. This method is simple and efficient, which can provide an effective method for rapidly screening tea varieties with high content of GABA. DART-MS method also has broad application in the fields of food active substance analysis, environmental organic pollutants, early screening of metabolic diseases and other fields.
2020, 48(9): 1260-1267
doi: 10.19756/j.issn.0253-3820.201244
Abstract:
A method for quantifying and characterizing the concentration of silver nanoparticles (AgNPs) in seawater by single-particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) was developed. The optimal residence time of SP-ICP-MS for detection of AgNPs was investigated. The influence of sea water matrix on detection of AgNPs was investigated, and the dilution ratio of sea water samples was determined. The results showed that the optimal dwell time of the instrument was 100 μs, and 150 times dilution of seawater could improve the accuracy of the determination of the concentration of AgNPs. The detection limit of the quantity concentration of AgNPs in seawater samples was 9.75×103 particles/mL, the detection limit of particle size was 12 nm, and the average recoveries of AgNPs with nominal particle sizes of 50 nm and 100 nm were above 70%. AgNPs were detected in the surface seawater samples of Dalian coastal waters. The maximum concentration was (2.1±0.004)×106 particles/mL, the minimum concentration was (1.1±0.01)×105 particles/mL, and the average particle size distribution was between 18 and 200 nm. This method showed many advantages including simple sample preparation, fast analysis speed and low detection limit of particle quantity and concentration. It provided a reliable analysis method for the monitoring and analysis of AgNPs in coastal seawater.
A method for quantifying and characterizing the concentration of silver nanoparticles (AgNPs) in seawater by single-particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) was developed. The optimal residence time of SP-ICP-MS for detection of AgNPs was investigated. The influence of sea water matrix on detection of AgNPs was investigated, and the dilution ratio of sea water samples was determined. The results showed that the optimal dwell time of the instrument was 100 μs, and 150 times dilution of seawater could improve the accuracy of the determination of the concentration of AgNPs. The detection limit of the quantity concentration of AgNPs in seawater samples was 9.75×103 particles/mL, the detection limit of particle size was 12 nm, and the average recoveries of AgNPs with nominal particle sizes of 50 nm and 100 nm were above 70%. AgNPs were detected in the surface seawater samples of Dalian coastal waters. The maximum concentration was (2.1±0.004)×106 particles/mL, the minimum concentration was (1.1±0.01)×105 particles/mL, and the average particle size distribution was between 18 and 200 nm. This method showed many advantages including simple sample preparation, fast analysis speed and low detection limit of particle quantity and concentration. It provided a reliable analysis method for the monitoring and analysis of AgNPs in coastal seawater.
2020, 48(9): 1268-1272
doi: 10.19756/j.issn.0253-3820.201174
Abstract:
Hydride generation-atomic fluorescence spectrometry is an ideal tool for determination of selenium (Se). But the detection results of Se in the plant samples were lower due to the volatilization loss in the digestion process. Our experiments found the volatilization loss of Se when the standard solution was digested with HCl, HF and HClO4, and heated to dryness, but there was no loss when it was digested with HNO3 alone, indicating that the volatilization may be related to the existing of F and Cl. In this study, a new method was proposed, which could effectively inhibit the volatilization of Se by adding Ca2+. After adding 8 mL 0.015 g/mL Ca2+ to 0.5000 g plant samples and digesting with the mixed solvent of HNO3-HClO4 (15:2, V/V) on low temperature heating plate, Se was not volatilized even after the solution was heated to dryness. Simultaneously, it was found that the addition of Ca2+ could not affect the allowable amount of the co-existing interference elements. The detection limit of the method was 4.95 ng/g, and the precision was 2.56%-3.17%. The determined values for the different reference materials of plant were in agreement with the certified values.
Hydride generation-atomic fluorescence spectrometry is an ideal tool for determination of selenium (Se). But the detection results of Se in the plant samples were lower due to the volatilization loss in the digestion process. Our experiments found the volatilization loss of Se when the standard solution was digested with HCl, HF and HClO4, and heated to dryness, but there was no loss when it was digested with HNO3 alone, indicating that the volatilization may be related to the existing of F and Cl. In this study, a new method was proposed, which could effectively inhibit the volatilization of Se by adding Ca2+. After adding 8 mL 0.015 g/mL Ca2+ to 0.5000 g plant samples and digesting with the mixed solvent of HNO3-HClO4 (15:2, V/V) on low temperature heating plate, Se was not volatilized even after the solution was heated to dryness. Simultaneously, it was found that the addition of Ca2+ could not affect the allowable amount of the co-existing interference elements. The detection limit of the method was 4.95 ng/g, and the precision was 2.56%-3.17%. The determined values for the different reference materials of plant were in agreement with the certified values.
2020, 48(9): 1273-1278
doi: 10.19756/j.issn.0253-3820.201189
Abstract:
Pepsin is an extremely important digestive enzyme in the stomach of mammals, which breaks down proteins in food by cutting off specific peptide bonds into amino acids. Pepsin is very sensitive to the pH of surroundings as a kind of acid protease, so the purpose of this experiment is to investigate the influence on the secondary structure of pepsin under various pH values and surfaces by Fourier transform infrared spectroscopy (FTIR) technology. The result shows that with the increase of pH, the percentage of β-sheet increases and reaches maximum in pH 3 to 7 and decreases when the solution is basic. The percentage of random coil is opposite to the β-sheet. When the ATR crystal surface is coated with TiO2, the percentage of β-sheet is much greater than other secondary structures. Moreover, with the change of pH, the percentage of each secondary structure has no significant change. At the same time, quantitative analysis shows that the interaction between pepsin and TiO2 is beneficial to the adsorption of pepsin on surface. It indicates that the functional groups can also affect the conformation of pepsin on the surface.
Pepsin is an extremely important digestive enzyme in the stomach of mammals, which breaks down proteins in food by cutting off specific peptide bonds into amino acids. Pepsin is very sensitive to the pH of surroundings as a kind of acid protease, so the purpose of this experiment is to investigate the influence on the secondary structure of pepsin under various pH values and surfaces by Fourier transform infrared spectroscopy (FTIR) technology. The result shows that with the increase of pH, the percentage of β-sheet increases and reaches maximum in pH 3 to 7 and decreases when the solution is basic. The percentage of random coil is opposite to the β-sheet. When the ATR crystal surface is coated with TiO2, the percentage of β-sheet is much greater than other secondary structures. Moreover, with the change of pH, the percentage of each secondary structure has no significant change. At the same time, quantitative analysis shows that the interaction between pepsin and TiO2 is beneficial to the adsorption of pepsin on surface. It indicates that the functional groups can also affect the conformation of pepsin on the surface.
