Login In
2018 Volume 46 Issue 1
2018, 46(1): 1-10
doi: 10.11895/j.issn.0253-3820.171054
Abstract:
Visualization detection methods are used for determination of the concentration of unknown target by comparing the color change in the intensity or type of reaction solution by naked eye. Visualization detection method has some advantages such as simple and rapid operation, low detection cost, fast reaction speed, and detecting target concentration by means of naked eye. Gold nanomaterials are widely used in the construction of visual biosensors due to its unique optical properties. For example, when changing the distance or morphology of the particles, the plasmon resonance absorption peak of local surface will change accordingly. Herein, we reviewed the application of gold nanomaterials in visualization biosensors for the detection of target molecules, summed up the main problems of AuNP colormertic methods in the determination of actual samples, and provided an outlook of the future of gold nanoparticles-based biosensor in application development.
Visualization detection methods are used for determination of the concentration of unknown target by comparing the color change in the intensity or type of reaction solution by naked eye. Visualization detection method has some advantages such as simple and rapid operation, low detection cost, fast reaction speed, and detecting target concentration by means of naked eye. Gold nanomaterials are widely used in the construction of visual biosensors due to its unique optical properties. For example, when changing the distance or morphology of the particles, the plasmon resonance absorption peak of local surface will change accordingly. Herein, we reviewed the application of gold nanomaterials in visualization biosensors for the detection of target molecules, summed up the main problems of AuNP colormertic methods in the determination of actual samples, and provided an outlook of the future of gold nanoparticles-based biosensor in application development.
2018, 46(1): 11-19
doi: 10.11895/j.issn.0253-3820.171275
Abstract:
Kinases are a class of enzymes that catalyze the transfer of a phosphate group from a high-energy molecule to their substrates (i.e., phosphorylation). Kinase-induced intracellular phosphorylation plays important roles in a variety of cellular processes including metabolism, cell signaling, protein regulation, DNA replication and repair. Consequently, kinases have become potential biomarkers for disease diagnosis and drug discovery, and the development of simple and sensitive methods for kinase assay is highly desirable. In this review, we summarize the recent advances in kinase assays with protein kinase A (PKA), casein kinase-2 (CKⅡ) and T4 polynucleotide kinase (T4 PNK) as the models. We focus on the newly emerging methods for kinase assays including fluorescent, single-molecule detection, colorimetric, chemiluminescent, bioluminescent, and electrochemical and photoelectrochemical methods. Furthermore, we give a new insight into the future direction of kinase assays.
Kinases are a class of enzymes that catalyze the transfer of a phosphate group from a high-energy molecule to their substrates (i.e., phosphorylation). Kinase-induced intracellular phosphorylation plays important roles in a variety of cellular processes including metabolism, cell signaling, protein regulation, DNA replication and repair. Consequently, kinases have become potential biomarkers for disease diagnosis and drug discovery, and the development of simple and sensitive methods for kinase assay is highly desirable. In this review, we summarize the recent advances in kinase assays with protein kinase A (PKA), casein kinase-2 (CKⅡ) and T4 polynucleotide kinase (T4 PNK) as the models. We focus on the newly emerging methods for kinase assays including fluorescent, single-molecule detection, colorimetric, chemiluminescent, bioluminescent, and electrochemical and photoelectrochemical methods. Furthermore, we give a new insight into the future direction of kinase assays.
2018, 46(1): 20-26
doi: 10.11895/j.issn.0253-3820.170114
Abstract:
A water-soluble fluorescent probe (7-diethyl amino-3-formaldehyde coumarin) for Fe3+ detection was designed and synthesized, and its structure was confirmed by 1HNMR, 13CNMR and MS spectra. This probe showed high emission intensity at 471 nm. With the continuous addition of Fe3+, the emission intensities at 471 nm decreased gradually, and showed an excellent linearity with Fe3+ in the range of 0.02-60 μmol/L, and the regression equation was I=322.56-4.86CFe3+. This probe was able to detect Fe3+ qualitatively and quantitatively with the detection limit as low as 22 nmol/L. Besides, this probe showed high sensitivity to Fe3+ over other metal ions. The detection process was reversible, which could be recycled for the Fe3+ detection. In terms of good optical properties and the strong fluorescence in physiological pH, the probe was successfully applied in imaging Fe3+ of living Ramos cells.
A water-soluble fluorescent probe (7-diethyl amino-3-formaldehyde coumarin) for Fe3+ detection was designed and synthesized, and its structure was confirmed by 1HNMR, 13CNMR and MS spectra. This probe showed high emission intensity at 471 nm. With the continuous addition of Fe3+, the emission intensities at 471 nm decreased gradually, and showed an excellent linearity with Fe3+ in the range of 0.02-60 μmol/L, and the regression equation was I=322.56-4.86CFe3+. This probe was able to detect Fe3+ qualitatively and quantitatively with the detection limit as low as 22 nmol/L. Besides, this probe showed high sensitivity to Fe3+ over other metal ions. The detection process was reversible, which could be recycled for the Fe3+ detection. In terms of good optical properties and the strong fluorescence in physiological pH, the probe was successfully applied in imaging Fe3+ of living Ramos cells.
2018, 46(1): 27-32
doi: 10.11895/j.issn.0253-3820.170206
Abstract:
In the present study, 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid (MTCA) was acted as hapten of thifluzamide to synthesize artificial antigens. Immunogen MTCA-bovine serum albumin (BSA) was synthesized by active ester method. Meanwhile, three coating antigens, MTCA-OVA-1, MTCA-OVA-2 and MTCA-OVA-3 were synthesized by active ester method, mixed anhydride method and N,N-carbonyldiimidazole/4-dimethylaminopyridine (CDI/DMAP) method, respectively. Anti-thifluzamide polyclonal antibody with high specificity was obtained from the immunized mice, then indirect competitive enzyme linked immunosorbent assay (ic-ELISA) method for thifluzamide detection was developed by using MTCA-OVA-3 and polyclonal antibody. The linear detection range in ic-ELISA was 0.08-10 mg/L with an IC50 of 1.39 mg/L and a LOD (IC10) of 0.08 mg/L. The recoveries for spiked samples including tap water, lake water and wheat ranged from 72.0%-128.3% in ic-ELISA method. Good correlation (R2=0.9994) was obtained between the results of ic-ELISA and those of HPLC analysis. The proposed ic-ELSA was promising for rapid detection of thifluzamide in water and agricultural products.
In the present study, 2-methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid (MTCA) was acted as hapten of thifluzamide to synthesize artificial antigens. Immunogen MTCA-bovine serum albumin (BSA) was synthesized by active ester method. Meanwhile, three coating antigens, MTCA-OVA-1, MTCA-OVA-2 and MTCA-OVA-3 were synthesized by active ester method, mixed anhydride method and N,N-carbonyldiimidazole/4-dimethylaminopyridine (CDI/DMAP) method, respectively. Anti-thifluzamide polyclonal antibody with high specificity was obtained from the immunized mice, then indirect competitive enzyme linked immunosorbent assay (ic-ELISA) method for thifluzamide detection was developed by using MTCA-OVA-3 and polyclonal antibody. The linear detection range in ic-ELISA was 0.08-10 mg/L with an IC50 of 1.39 mg/L and a LOD (IC10) of 0.08 mg/L. The recoveries for spiked samples including tap water, lake water and wheat ranged from 72.0%-128.3% in ic-ELISA method. Good correlation (R2=0.9994) was obtained between the results of ic-ELISA and those of HPLC analysis. The proposed ic-ELSA was promising for rapid detection of thifluzamide in water and agricultural products.
2018, 46(1): 33-38
doi: 10.11895/j.issn.0253-3820.171059
Abstract:
By using zinc nitrate as precursor and hydrazine hydrate as reducing agent, polydiallyl dimethyl ammonium chloride modified reduced graphene oxide/zinc oxide composite materials (PDDA-rGO/ZnO) were prepared by simultaneous reduction of graphene oxide (GO) and zinc nitrate. The composite materials were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometer (XRD) and transmission electron microscopy (TEM), and their electrochemical catalytic activity for uric acid was studied by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) measurements. The result showed that PDDA-rGO/ZnO modified glassy carbon electrode prepared here was sensitive, reproducible and stable, and had significant electrocatalytic activity for UA. When using linear sweep voltammetry for detection of UA, the responses of modified electrode were linear with UA concentration in the ranges of 0.02-0.1 mmol/L and 0.1-1.0 mmol/L respectively, with detection limit of 15.9 nmol/L (S/N=3).
By using zinc nitrate as precursor and hydrazine hydrate as reducing agent, polydiallyl dimethyl ammonium chloride modified reduced graphene oxide/zinc oxide composite materials (PDDA-rGO/ZnO) were prepared by simultaneous reduction of graphene oxide (GO) and zinc nitrate. The composite materials were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometer (XRD) and transmission electron microscopy (TEM), and their electrochemical catalytic activity for uric acid was studied by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) measurements. The result showed that PDDA-rGO/ZnO modified glassy carbon electrode prepared here was sensitive, reproducible and stable, and had significant electrocatalytic activity for UA. When using linear sweep voltammetry for detection of UA, the responses of modified electrode were linear with UA concentration in the ranges of 0.02-0.1 mmol/L and 0.1-1.0 mmol/L respectively, with detection limit of 15.9 nmol/L (S/N=3).
2018, 46(1): 39-47
doi: 10.11895/j.issn.0253-3820.171163
Abstract:
Hydrogen sulfide (H2S) has been confirmed as a significant endogenous gaseous signaling molecule involved in various physiological processes. To monitor H2S in living cells, a Förster resonance energy transfer (FRET) ratiometric probe based on quantum dot-cresyl violet was developed. In this work, quantum dot nanospheres (QDS) were firstly synthesized via a facile ultrasonication emulsion strategy, and the mixture chloroform solution containing hydrophobic quantum dots and COOH-functionalized amphiphilic polymer were successfully transferred into the oil-in-water micelle. The negatively charged quantum dot nanospheres with quantum dots embedded in the polymer matrixes were successfully fabricated after the evaporation of chloroform. And then, these quantum dot nanospheres were condensed with positively charged cresyl violet-azide (CV-N3) via electrostatic interaction to obtain the QDS-N3 complexes. The as-prepared QDS-N3 complexes were monodispersed nanospheres with an average diameter of about 120 nm. These complexes were taken up by the cell through endocytosis, and they were still stable even in wide pH range. In addition, the QDS-N3 complexes exhibited no cellular toxicity which was verified by MTT assay. In this ratiometric probe, CV-N3 as a FRET acceptor was conjugated to quantum dot nanospheres. The quantum dots emitted at 591 nm and served as the FRET donor; once the aryl azide on the CV-N3 was reduced to aniline by H2S, the probe emitted at 620 nm. The ratiometric probe allowed the elimination of interference of excitation intensity, intracellular environment and other factors. Furthermore, this method also offered a general protocol for preparing nanosensors for monitoring various small molecular in living cells.
Hydrogen sulfide (H2S) has been confirmed as a significant endogenous gaseous signaling molecule involved in various physiological processes. To monitor H2S in living cells, a Förster resonance energy transfer (FRET) ratiometric probe based on quantum dot-cresyl violet was developed. In this work, quantum dot nanospheres (QDS) were firstly synthesized via a facile ultrasonication emulsion strategy, and the mixture chloroform solution containing hydrophobic quantum dots and COOH-functionalized amphiphilic polymer were successfully transferred into the oil-in-water micelle. The negatively charged quantum dot nanospheres with quantum dots embedded in the polymer matrixes were successfully fabricated after the evaporation of chloroform. And then, these quantum dot nanospheres were condensed with positively charged cresyl violet-azide (CV-N3) via electrostatic interaction to obtain the QDS-N3 complexes. The as-prepared QDS-N3 complexes were monodispersed nanospheres with an average diameter of about 120 nm. These complexes were taken up by the cell through endocytosis, and they were still stable even in wide pH range. In addition, the QDS-N3 complexes exhibited no cellular toxicity which was verified by MTT assay. In this ratiometric probe, CV-N3 as a FRET acceptor was conjugated to quantum dot nanospheres. The quantum dots emitted at 591 nm and served as the FRET donor; once the aryl azide on the CV-N3 was reduced to aniline by H2S, the probe emitted at 620 nm. The ratiometric probe allowed the elimination of interference of excitation intensity, intracellular environment and other factors. Furthermore, this method also offered a general protocol for preparing nanosensors for monitoring various small molecular in living cells.
2018, 46(1): 48-54
doi: 10.11895/j.issn.0253-3820.170331
Abstract:
The anhydrite and gypsum are the main sulfate minerals during evaporation of seawater or lake. They record the information about relative hydrogeology and the composition of mother liquor. Boron is diffluent element, and often occurs in all kinds of evaporites. Presently, the boron isotope has been applied widely in mineral deposits forming, geochemistry and palaeoenvironment. However, there is little research about characteristic of boron isotope in anhydrite and gypsum minerals, because of the low content of boron and micro-solubility in water and hydrochloric acid. This study developed a method of extracting and purifying boron in anhydrite and gypsum by phase transformation and ion-exchange. Firstly, the samples were mixed with ammonium hydrogen carbonate to transform the calcium sulfate to calcium carbonate. And diluted hydrochloric acid (1 mol/L) was added to resolve calcium carbonate. The percent conversion was about 85% in the first stage, and up to complete resolution by repeating this process. Secondly, boron specific ion-exchange resin (Amberlite IRA 743) was used to gather the boron ions fully and further refined the samples with more than 1 μg of boron by anionic and cationic resin mixed by Ion Exchange Ⅱ and Dowex 50 W×8. Finally, according to the modified method by He, the values of boron isotope were determined by TIMS. The boron content is analytically pure gypsum was 3.501±0.128 μg/g (n=12, RSD=3.6%) and the average recovery was 100.47%. Besides, the δ11B value of analytically pure gypsum added with NIST SRM 951 was 17.98‰±0.21‰ (n=3, RSD=1.2%). This method has good repeatability and can meet the requirements of boron isotopic measurement of anhydrite and gypsum.
The anhydrite and gypsum are the main sulfate minerals during evaporation of seawater or lake. They record the information about relative hydrogeology and the composition of mother liquor. Boron is diffluent element, and often occurs in all kinds of evaporites. Presently, the boron isotope has been applied widely in mineral deposits forming, geochemistry and palaeoenvironment. However, there is little research about characteristic of boron isotope in anhydrite and gypsum minerals, because of the low content of boron and micro-solubility in water and hydrochloric acid. This study developed a method of extracting and purifying boron in anhydrite and gypsum by phase transformation and ion-exchange. Firstly, the samples were mixed with ammonium hydrogen carbonate to transform the calcium sulfate to calcium carbonate. And diluted hydrochloric acid (1 mol/L) was added to resolve calcium carbonate. The percent conversion was about 85% in the first stage, and up to complete resolution by repeating this process. Secondly, boron specific ion-exchange resin (Amberlite IRA 743) was used to gather the boron ions fully and further refined the samples with more than 1 μg of boron by anionic and cationic resin mixed by Ion Exchange Ⅱ and Dowex 50 W×8. Finally, according to the modified method by He, the values of boron isotope were determined by TIMS. The boron content is analytically pure gypsum was 3.501±0.128 μg/g (n=12, RSD=3.6%) and the average recovery was 100.47%. Besides, the δ11B value of analytically pure gypsum added with NIST SRM 951 was 17.98‰±0.21‰ (n=3, RSD=1.2%). This method has good repeatability and can meet the requirements of boron isotopic measurement of anhydrite and gypsum.
2018, 46(1): 55-60
doi: 10.11895/j.issn.0253-3820.171261
Abstract:
Oligosaccharide isomers were distinguished by electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry (ECD-FT-ICR-MS) in combination with utilizing alkali, alkaline earth, and transition metals (Na+, Ca2+, Ba2+,Mg2+, Mn2+ and Co2+) as charge carriers in electrospray. Maltoheptaose, mannohexaose and laminarihexaose were taken as examples to investigate influence of metal ions on the extent of oligosaccharide fragmentation. The same types of fragmentation ions (0,2A and 2,4A) were obtained for barium-and calcium-adducted maltoheptaose. Mg2+ and Mn2+ had the similar influence (0,2A, 2,4A and 2,5A). Three cross-ring cleavage ions (1,4A, 2,4A and 2,5A) were generated in the spectrum of cobalt-associated maltoheptaose. But in the case of doping Na+ into maltoheptaose, only 0,2A ion was detected. It was found that the signals in the spectra of mannohexaose and laminarihexaose were worse than that in the spectrum of maltoheptaose, probably resulting from different numbers of adducted metal ions. The isomers, mannohexaose and laminarihexaose could be distinguished by ECD-MS in conjunction with the addition of Ca2+, Mg2+ or Co2+. The addition of Ca2+ was the best choice for analysis of oligosaccharides.
Oligosaccharide isomers were distinguished by electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry (ECD-FT-ICR-MS) in combination with utilizing alkali, alkaline earth, and transition metals (Na+, Ca2+, Ba2+,Mg2+, Mn2+ and Co2+) as charge carriers in electrospray. Maltoheptaose, mannohexaose and laminarihexaose were taken as examples to investigate influence of metal ions on the extent of oligosaccharide fragmentation. The same types of fragmentation ions (0,2A and 2,4A) were obtained for barium-and calcium-adducted maltoheptaose. Mg2+ and Mn2+ had the similar influence (0,2A, 2,4A and 2,5A). Three cross-ring cleavage ions (1,4A, 2,4A and 2,5A) were generated in the spectrum of cobalt-associated maltoheptaose. But in the case of doping Na+ into maltoheptaose, only 0,2A ion was detected. It was found that the signals in the spectra of mannohexaose and laminarihexaose were worse than that in the spectrum of maltoheptaose, probably resulting from different numbers of adducted metal ions. The isomers, mannohexaose and laminarihexaose could be distinguished by ECD-MS in conjunction with the addition of Ca2+, Mg2+ or Co2+. The addition of Ca2+ was the best choice for analysis of oligosaccharides.
Metal/Matrix Enhanced Time-of-Flight Secondary Ion Mass Spectrometry for Single Cell Lipids Analysis
2018, 46(1): 61-66
doi: 10.11895/j.issn.0253-3820.171014
Abstract:
The chemical components analysis of single cell is important for understanding of physiological processes such as cell growth, signal transduction and apoptosis. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a sensitive surface analysis technique with high spatial resolution and can be used for single cell and micro-area analysis. However, relatively low ionization yield of biomolecules limited its wide application in single cell analysis. Herein, we used metal substrate and matrix material to enhance the ionization yield of lipids. The signal intensity of the phosphatidylcholine PC (40:0) casted on the matrix/gold coated silicon substrate was 65 times higher than that on the silicon wafer. Signal enhancement of phosphatidylcholine PC (34:1) on the single cell surface cultured on matrix/gold coated silicon substrate was observed as well. Due to the influence of irregular topography and complex chemical environment of cell, the increase of lipids signal was smaller. Delayed extraction mode of ToF-SIMS overcame the effects of cell topography, leading to further enhancement of the signal intensity of lipids. Meanwhile, simultaneous high spatial resolution of chemical imaging and high mass resolution of the mass spectra of single cells were obtained. Our strategies provided new insights into the study of cell metabolism and cell-environment interactions.
The chemical components analysis of single cell is important for understanding of physiological processes such as cell growth, signal transduction and apoptosis. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a sensitive surface analysis technique with high spatial resolution and can be used for single cell and micro-area analysis. However, relatively low ionization yield of biomolecules limited its wide application in single cell analysis. Herein, we used metal substrate and matrix material to enhance the ionization yield of lipids. The signal intensity of the phosphatidylcholine PC (40:0) casted on the matrix/gold coated silicon substrate was 65 times higher than that on the silicon wafer. Signal enhancement of phosphatidylcholine PC (34:1) on the single cell surface cultured on matrix/gold coated silicon substrate was observed as well. Due to the influence of irregular topography and complex chemical environment of cell, the increase of lipids signal was smaller. Delayed extraction mode of ToF-SIMS overcame the effects of cell topography, leading to further enhancement of the signal intensity of lipids. Meanwhile, simultaneous high spatial resolution of chemical imaging and high mass resolution of the mass spectra of single cells were obtained. Our strategies provided new insights into the study of cell metabolism and cell-environment interactions.
2018, 46(1): 67-73
doi: 10.11895/j.issn.0253-3820.171412
Abstract:
This work aims to analyze and compare the potential biomarkers between cervical cancer (CC) patients and healthy controls (HC). The urine samples of 11 CC patients (age (45.65 ±5.6) years) and 11 HC patients (age (45.9 ±3.2) years) were collected. The metabolites of urine samples from CC and HC were analyzed by using ultra performance liquid chromatography coupled with quadrupole orbitrap tandem mass spectrometry (UHPLC-Q-Orbitrap MS/MS), which could provide evidence for early diagnose and disease pathway. The LC-MS data of urines were analyzed by principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to identify the potential biomarkers. Urine samples of CC patients were successfully discirminated from those of healthy controls. A total of twelve significant metabolites were found and identified as potential biomarkers according to the established UHPLC-Q-Orbitrap MS and MS/MS method. Identification of biomarkers between CC and HC patients may play an important role in the study of mechanism of UC and its pathway.
This work aims to analyze and compare the potential biomarkers between cervical cancer (CC) patients and healthy controls (HC). The urine samples of 11 CC patients (age (45.65 ±5.6) years) and 11 HC patients (age (45.9 ±3.2) years) were collected. The metabolites of urine samples from CC and HC were analyzed by using ultra performance liquid chromatography coupled with quadrupole orbitrap tandem mass spectrometry (UHPLC-Q-Orbitrap MS/MS), which could provide evidence for early diagnose and disease pathway. The LC-MS data of urines were analyzed by principal components analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to identify the potential biomarkers. Urine samples of CC patients were successfully discirminated from those of healthy controls. A total of twelve significant metabolites were found and identified as potential biomarkers according to the established UHPLC-Q-Orbitrap MS and MS/MS method. Identification of biomarkers between CC and HC patients may play an important role in the study of mechanism of UC and its pathway.
2018, 46(1): 74-80
doi: 10.11895/j.issn.0253-3820.171206
Abstract:
It is one of the necessary work in oil and gas exploration and development to record the logging of different depth cuttings. In this study, a laser induced breakdown spectrometer (LIBS-Trace) developed by our research group was used for the lithology logging in the field of oil and gas exploration and development. A total of 60 samples from a drilling site in the Southwest China were divided into training set and test set, and then element quantitative analysis model of eight elements of Si, Al, Ca, K, Mg, Mn, Ti and Fe was established based on support vector machine regression (SVR). The results showed that the mean percentage prediction errors (MPE) predicted by this method were Si 5.68%, Al 7.22%, Ca 7.45%, K 9.76%, Mg 8.79%, Mn 11.9%, Ti 11.4% and Fe 10.4%, which met the requirements of logging work. In addition, according to the logging process and demand, the instrument hardware and software were modified, and the quantitative model integrated in the instrument was optimized. The results showed that the algorithm model combined with the instrument could quickly complete the quantitative analysis of rock debris samples, and exhibited potential application value and broad application prospect in oil and gas exploration and development.
It is one of the necessary work in oil and gas exploration and development to record the logging of different depth cuttings. In this study, a laser induced breakdown spectrometer (LIBS-Trace) developed by our research group was used for the lithology logging in the field of oil and gas exploration and development. A total of 60 samples from a drilling site in the Southwest China were divided into training set and test set, and then element quantitative analysis model of eight elements of Si, Al, Ca, K, Mg, Mn, Ti and Fe was established based on support vector machine regression (SVR). The results showed that the mean percentage prediction errors (MPE) predicted by this method were Si 5.68%, Al 7.22%, Ca 7.45%, K 9.76%, Mg 8.79%, Mn 11.9%, Ti 11.4% and Fe 10.4%, which met the requirements of logging work. In addition, according to the logging process and demand, the instrument hardware and software were modified, and the quantitative model integrated in the instrument was optimized. The results showed that the algorithm model combined with the instrument could quickly complete the quantitative analysis of rock debris samples, and exhibited potential application value and broad application prospect in oil and gas exploration and development.
2018, 46(1): 81-87
doi: 10.11895/j.issn.0253-3820.171088
Abstract:
A new all-solid state electrode modified with poly(o-aminophenol-co-o-phenylenediamine) film was prepared by cyclic voltammetry. The electrochemical response of the electrode to various solutions in the available acidity range of 1.00×10-12-10.0 mol/L was studied by cyclic voltammetry. The results showed that the reduction peak potentials and the available acidity of solution showed good linear relationship in 3 stages of 1.00×10-10-0.10 mol/L, 0.10-2.00 mol/L and 2.00-10.0 mol/L respectively, and the regression equations were Epc=0.0456lgC(H+)-0.295, Epc=0.0803c(H+)-0.309, and Epc=0.0278c(H+)-0.188, respectively. There were similar responses in the solutions of H2SO4, HNO3 and HClO4 in the concentration range of 1.00-8.00 mol/L. The preparation method of electrode was simple, and the determination range of available acidity was as wide as 1.0×10-10-10.0 mol/L, which laid the foundation for the development of solid-state electrochemical sensors for determination of acidity of high acidity solution.
A new all-solid state electrode modified with poly(o-aminophenol-co-o-phenylenediamine) film was prepared by cyclic voltammetry. The electrochemical response of the electrode to various solutions in the available acidity range of 1.00×10-12-10.0 mol/L was studied by cyclic voltammetry. The results showed that the reduction peak potentials and the available acidity of solution showed good linear relationship in 3 stages of 1.00×10-10-0.10 mol/L, 0.10-2.00 mol/L and 2.00-10.0 mol/L respectively, and the regression equations were Epc=0.0456lgC(H+)-0.295, Epc=0.0803c(H+)-0.309, and Epc=0.0278c(H+)-0.188, respectively. There were similar responses in the solutions of H2SO4, HNO3 and HClO4 in the concentration range of 1.00-8.00 mol/L. The preparation method of electrode was simple, and the determination range of available acidity was as wide as 1.0×10-10-10.0 mol/L, which laid the foundation for the development of solid-state electrochemical sensors for determination of acidity of high acidity solution.
2018, 46(1): 88-93
doi: 10.11895/j.issn.0253-3820.170003
Abstract:
The melamine molecular imprinted polymer (MIP) membrane immobilized on the surface of the surface plasmon resonance (SPR) chip was prepared with allylcyanurate and ethylene glycol dimethacrylate as a functional monomer and cross-linker, respectively. Based on the ratio of the intercept to the slope of Langmuir equation for imprinted polymer, the association constant (Kass) of imprinted sites in the imprinted film to melamine was calculated to be 1.40×108 L/mol. The SPR sensor showed high selectivity to the template molecule melamine, and the best response was obtained at pH=7.5. The method showed good linearity in the melamine concentration range of 0.1-10.0 nmol/L (R=0.9991). Based on a signal to noise ratio of 3, the detection limits of melamine were 62.6 pmol/L and 56.4 pmol/L for the milk and milk powder, respectively. The recoveries were 91.5% for milk and 92.0% for milk powder. These results suggest that SPR sensing combined with MIP film is a promising alternative method for detection of melamine.
The melamine molecular imprinted polymer (MIP) membrane immobilized on the surface of the surface plasmon resonance (SPR) chip was prepared with allylcyanurate and ethylene glycol dimethacrylate as a functional monomer and cross-linker, respectively. Based on the ratio of the intercept to the slope of Langmuir equation for imprinted polymer, the association constant (Kass) of imprinted sites in the imprinted film to melamine was calculated to be 1.40×108 L/mol. The SPR sensor showed high selectivity to the template molecule melamine, and the best response was obtained at pH=7.5. The method showed good linearity in the melamine concentration range of 0.1-10.0 nmol/L (R=0.9991). Based on a signal to noise ratio of 3, the detection limits of melamine were 62.6 pmol/L and 56.4 pmol/L for the milk and milk powder, respectively. The recoveries were 91.5% for milk and 92.0% for milk powder. These results suggest that SPR sensing combined with MIP film is a promising alternative method for detection of melamine.
2018, 46(1): 94-99
doi: 10.11895/j.issn.0253-3820.171220
Abstract:
As an important inorganic element, iodine not only plays an important role in human growth and metabolism, but also has an irreplaceable role in the chemical engineering, medicine, food and other fields. Thus the detection of iodine ion is of important significance. In this work, colorimetric recognition and sensing of iodine ion with high sensitivity was proposed based on target induced shielding of the peroxidase-like activity of bare platinum nanoparticles (PtNPs). This assay exhibited simplicity and cost-effectiveness. The recognition of iodine ion by bare PtNPs could be fulfilled in a few seconds and the assay could be accomplished within 10 min. The detection range for iodine ion was 20 nmol/L-5.0 μmol/L and the detection limit was 8 nmol/L (S/N=3). Furthermore, the new assay system did not require surface modification of nanoparticles, nor complex organic synthesis. This assay was successfully applied to detection of iodine concentration in real salt and water samples, exhibiting promising application prospects.
As an important inorganic element, iodine not only plays an important role in human growth and metabolism, but also has an irreplaceable role in the chemical engineering, medicine, food and other fields. Thus the detection of iodine ion is of important significance. In this work, colorimetric recognition and sensing of iodine ion with high sensitivity was proposed based on target induced shielding of the peroxidase-like activity of bare platinum nanoparticles (PtNPs). This assay exhibited simplicity and cost-effectiveness. The recognition of iodine ion by bare PtNPs could be fulfilled in a few seconds and the assay could be accomplished within 10 min. The detection range for iodine ion was 20 nmol/L-5.0 μmol/L and the detection limit was 8 nmol/L (S/N=3). Furthermore, the new assay system did not require surface modification of nanoparticles, nor complex organic synthesis. This assay was successfully applied to detection of iodine concentration in real salt and water samples, exhibiting promising application prospects.
2018, 46(1): 100-106
doi: 10.11895/j.issn.0253-3820.170163
Abstract:
The magnetic molecularly imprinted polymers (MMIPs) was synthesized by suspension polymers technique using ornidazole (ONZ) as template, and methacrylic acid (MAA) and acrylamide (AA) as the binary functional monomers. The MMIPs were characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA) and ultraviolet-visible (UV-Vis) spectrophotometer. The results indicated that the adsorption capacity of MMIPs using the binary functional monomers to ONZ was higher than that using single functional monomer or that of its structural analogues. The Scatchard plot revealed that the template polymer system had a two-site binding behavior and the MMIPs exhibited the maximum rebinding to ONZ at 48.96 μmol/g and 10.60 μmol/g. Combined with high performance liquid chromatographic analysis technology, the prepared MMIPs were successfully applied to extract and enrich trace nitroimidazoles from river water samples with recoveries range of 85.4%-104.3%. The precision of the results was good, and the manipulation of the developed method was simple and fast comparing to other methods.
The magnetic molecularly imprinted polymers (MMIPs) was synthesized by suspension polymers technique using ornidazole (ONZ) as template, and methacrylic acid (MAA) and acrylamide (AA) as the binary functional monomers. The MMIPs were characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA) and ultraviolet-visible (UV-Vis) spectrophotometer. The results indicated that the adsorption capacity of MMIPs using the binary functional monomers to ONZ was higher than that using single functional monomer or that of its structural analogues. The Scatchard plot revealed that the template polymer system had a two-site binding behavior and the MMIPs exhibited the maximum rebinding to ONZ at 48.96 μmol/g and 10.60 μmol/g. Combined with high performance liquid chromatographic analysis technology, the prepared MMIPs were successfully applied to extract and enrich trace nitroimidazoles from river water samples with recoveries range of 85.4%-104.3%. The precision of the results was good, and the manipulation of the developed method was simple and fast comparing to other methods.
2018, 46(1): 107-112
doi: 10.11895/j.issn.0253-3820.171061
Abstract:
An analytical method was proposed to determine the ultra-trace metal elements in high-purity tetramethylammonium hydroxide (TMAH). A total of 12 kinds of ultra-trace metal elements in 25% (w/w) high-purity TMAH aqueous solution were directly determined after simple dilution with ultrapure water by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). In MS/MS mode, the spectral interferences were eliminated by the reaction of target ions with O2 or NH3/He (1:9, V/V) in the collision/reaction cell (CRC) of the ICP-MS/MS. Cr, Mn, Ni and Mo were determined using the O2 mass shift method. Cd and Pb were analyzed based on the O2 on-mass method. Fe, Co, Cu and Zn were determined using the NH3/He mass shift method. Mg and Al were determined using the NH3/He on-mass. The detection limits for analytes were in the range of 0.3-57.2 ng/L. The spiked recoveries were in range of 92.0%-106.0%, and the relative standard deviations (RSDs) were less than or equal to 4.6%. The procedure was applied for determining ultra-trace metal elements in 25% high-purity TMAH aqueous solution.
An analytical method was proposed to determine the ultra-trace metal elements in high-purity tetramethylammonium hydroxide (TMAH). A total of 12 kinds of ultra-trace metal elements in 25% (w/w) high-purity TMAH aqueous solution were directly determined after simple dilution with ultrapure water by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). In MS/MS mode, the spectral interferences were eliminated by the reaction of target ions with O2 or NH3/He (1:9, V/V) in the collision/reaction cell (CRC) of the ICP-MS/MS. Cr, Mn, Ni and Mo were determined using the O2 mass shift method. Cd and Pb were analyzed based on the O2 on-mass method. Fe, Co, Cu and Zn were determined using the NH3/He mass shift method. Mg and Al were determined using the NH3/He on-mass. The detection limits for analytes were in the range of 0.3-57.2 ng/L. The spiked recoveries were in range of 92.0%-106.0%, and the relative standard deviations (RSDs) were less than or equal to 4.6%. The procedure was applied for determining ultra-trace metal elements in 25% high-purity TMAH aqueous solution.
2018, 46(1): 113-120
doi: 10.11895/j.issn.0253-3820.171046
Abstract:
An open-access microfluidic chip which enabled automatic cell distribution and complex multi-step operations was developed. The microfluidic chip featured a key structure in which a nanoporous membrane was sandwiched by a cell culture chamber array layer and a corresponding media reservoir array layer. The microfluidic approach took advantage of the characteristics of the nanoporous membrane. On one side, this membrane permitted the flow of air but not liquid, thus acting as a flow-stop valve to enable automatic cell distribution. On the other side, it allowed diffusion-based media exchange and thus, mimicked the endothelial layer. In synergy with a liquid transferring platform, the open-access microfluidic system enabled complex multi-step operations involving medium exchange, drug treatment, and cell viability testing. By using this microfluidic protocol, a 10×10 tissue arrays was constructed in 90 s, followed by schedule-dependent drug testing. Morphological and immunohistochemical assays results indicated that the resultant tumor tissue was faithful to that in vivo. Drug testing assays showed that the microfluidic tissue array promised multi-step cell assays under biomimetic microenvironment, thus providing an advantageous tool for cell research.
An open-access microfluidic chip which enabled automatic cell distribution and complex multi-step operations was developed. The microfluidic chip featured a key structure in which a nanoporous membrane was sandwiched by a cell culture chamber array layer and a corresponding media reservoir array layer. The microfluidic approach took advantage of the characteristics of the nanoporous membrane. On one side, this membrane permitted the flow of air but not liquid, thus acting as a flow-stop valve to enable automatic cell distribution. On the other side, it allowed diffusion-based media exchange and thus, mimicked the endothelial layer. In synergy with a liquid transferring platform, the open-access microfluidic system enabled complex multi-step operations involving medium exchange, drug treatment, and cell viability testing. By using this microfluidic protocol, a 10×10 tissue arrays was constructed in 90 s, followed by schedule-dependent drug testing. Morphological and immunohistochemical assays results indicated that the resultant tumor tissue was faithful to that in vivo. Drug testing assays showed that the microfluidic tissue array promised multi-step cell assays under biomimetic microenvironment, thus providing an advantageous tool for cell research.
2018, 46(1): 121-128
doi: 10.11895/j.issn.0253-3820.171115
Abstract:
An ultra-high performance liquid chromatography tandem mass spectrometric (LC-MS/MS) method for simultaneous determination of 8 kinds of neurotransmitters (5-HT, GABA, Glu, ACH, NE, DA, 5-HIAA, HVA) in rat serum was developed. The blood samples were extracted by 0.1% formic acid in acetonitrile and separated on a Waters ACQUITY UPLC BEH C18 (2.1 mm×100 mm, 1.7 μm) using gradient elution, with the mobile phase consisting of acetonitrile and 0.1% formic acid in water. The samples were then ionized with positive electrospray (ESI+), and detected under multiple reaction monitoring (MRM) mode. As a result, 8 kinds of neurotransmitters were determined accurately in 10 min with a limit of quantitation of 1.8 ng/mL and intra-day and inter-day precisions of ≤ 9.2% (n=6). This method showed a good linearity in detection of neurotransmitters and the linear correlation coefficients were greater than 0.994. Also the stability, recovery and matrix effect were eligible for the analysis. This method showed high accuracy, sensitivity, strong specificity, good stability, small matrix effect and short time for analysis, and was suitable for the quantitative determination of monoamine, amino acids and acetylcholine neurotransmittes in rat serum.
An ultra-high performance liquid chromatography tandem mass spectrometric (LC-MS/MS) method for simultaneous determination of 8 kinds of neurotransmitters (5-HT, GABA, Glu, ACH, NE, DA, 5-HIAA, HVA) in rat serum was developed. The blood samples were extracted by 0.1% formic acid in acetonitrile and separated on a Waters ACQUITY UPLC BEH C18 (2.1 mm×100 mm, 1.7 μm) using gradient elution, with the mobile phase consisting of acetonitrile and 0.1% formic acid in water. The samples were then ionized with positive electrospray (ESI+), and detected under multiple reaction monitoring (MRM) mode. As a result, 8 kinds of neurotransmitters were determined accurately in 10 min with a limit of quantitation of 1.8 ng/mL and intra-day and inter-day precisions of ≤ 9.2% (n=6). This method showed a good linearity in detection of neurotransmitters and the linear correlation coefficients were greater than 0.994. Also the stability, recovery and matrix effect were eligible for the analysis. This method showed high accuracy, sensitivity, strong specificity, good stability, small matrix effect and short time for analysis, and was suitable for the quantitative determination of monoamine, amino acids and acetylcholine neurotransmittes in rat serum.
2018, 46(1): 129-135
doi: 10.11895/j.issn.0253-3820.171043
Abstract:
A method has been developed by solid phase extraction-high performance liquid chromatography coupled with photodiode array detector for simultaneous determination of 10 kinds of cyanotoxins in lake water, including microcystin-RR (MC-RR), MC-YR, MC-HtyR, MC-LR, MC-WR, MC-LA, MC-LY, MC-LW, MC-LF and nodularin (NOD). The samples were enriched and purified by a HLB solid phase extraction column. The separation was performed on a Waters C18 column (250 mm×4.6 mm, 5 μm) with the gradient elution of acetonitrile and water containing 0.05% trifluoroacetic acid. The flow rate of the mobile phase was 0.8 mL/min. The column temperature was 30℃ and the injection volume was 20 μL. The photodiode array detector was scanned from 190 nm to 300 nm and the detection wavelength was 238 nm. Multiple qualitative analyses were completed according to retention time, full scanning spectrum of photodiode array detector and purity analysis of chromatographic peak. Good linearity was observed in the cyanotoxin concentration range of 0.05 mg/L-2.0 mg/L with correlation coefficients (R) from 0.9998 to 0.9999. The limits of detection for 10 cyanotoxins were in the range of 0.005 μg/L-0.020 μg/L. The recoveries were in the range of 85.1%-105.3% at the three spiked levels of 0.1 mg/L, 1.0 mg/L and 1.8 mg/L with the relative standard deviations (RSD) of 0.8%-9.2%. The method was characterized by wide applicability, convenient operation, quick analytical rate, high sensitivity, good accuracy and high recovery. The qualitative accuracy was improved by using multiple qualitative analyses. This method was successfully applied to determination of 10 kinds of cyanotoxins in lake water.
A method has been developed by solid phase extraction-high performance liquid chromatography coupled with photodiode array detector for simultaneous determination of 10 kinds of cyanotoxins in lake water, including microcystin-RR (MC-RR), MC-YR, MC-HtyR, MC-LR, MC-WR, MC-LA, MC-LY, MC-LW, MC-LF and nodularin (NOD). The samples were enriched and purified by a HLB solid phase extraction column. The separation was performed on a Waters C18 column (250 mm×4.6 mm, 5 μm) with the gradient elution of acetonitrile and water containing 0.05% trifluoroacetic acid. The flow rate of the mobile phase was 0.8 mL/min. The column temperature was 30℃ and the injection volume was 20 μL. The photodiode array detector was scanned from 190 nm to 300 nm and the detection wavelength was 238 nm. Multiple qualitative analyses were completed according to retention time, full scanning spectrum of photodiode array detector and purity analysis of chromatographic peak. Good linearity was observed in the cyanotoxin concentration range of 0.05 mg/L-2.0 mg/L with correlation coefficients (R) from 0.9998 to 0.9999. The limits of detection for 10 cyanotoxins were in the range of 0.005 μg/L-0.020 μg/L. The recoveries were in the range of 85.1%-105.3% at the three spiked levels of 0.1 mg/L, 1.0 mg/L and 1.8 mg/L with the relative standard deviations (RSD) of 0.8%-9.2%. The method was characterized by wide applicability, convenient operation, quick analytical rate, high sensitivity, good accuracy and high recovery. The qualitative accuracy was improved by using multiple qualitative analyses. This method was successfully applied to determination of 10 kinds of cyanotoxins in lake water.
2018, 46(1): 136-142
doi: 10.11895/j.issn.0253-3820.171158
Abstract:
Near-infrared spectroscopy (NIR) is widely used in the area of food quantitative and qualitative analysis. Variable selection technique is a critical step of the spectrum modeling with the development of chemometrics. In this study, a novel variable selection strategy, automatic weighting variable combination population analysis (AWVCPA), was proposed. Firstly, binary matrix sampling (BMS) strategy that gives each variable the same chance to be selected and generates different variable combinations, was used to produce a population of subsets to construct a population of sub-models. Then, the variable frequency (Fre) and partial least squares regression (Reg), which were two kinds of information vector (IVs) were weighted to obtain the value of the contribution of each spectral variables, the influence of two IVs of Rre and Reg was considered to each spectral variable. Finally, it used the exponentially decreasing function (EDF) to remove the low contribution wavelengths so as to select the characteristic variable. In the case of near infrared spectrum of beer and corn, the prediction model based on partial least squares (PLS) was established. Compared with other variable selection methods, the research showed that AWVCPA was the best variable selection strategy in the same situation. It had 72.7% improvement compared AWVCPA-PLS with PLS and the predicted root mean square error (RMSEP) decreased from 0.5348 to 0.1457 on beer dataset. It had 64.7% improvement compared AWVCPA-PLS with PLS and the RMSEP decreased from 0.0702 to 0.0248 on corn dataset.
Near-infrared spectroscopy (NIR) is widely used in the area of food quantitative and qualitative analysis. Variable selection technique is a critical step of the spectrum modeling with the development of chemometrics. In this study, a novel variable selection strategy, automatic weighting variable combination population analysis (AWVCPA), was proposed. Firstly, binary matrix sampling (BMS) strategy that gives each variable the same chance to be selected and generates different variable combinations, was used to produce a population of subsets to construct a population of sub-models. Then, the variable frequency (Fre) and partial least squares regression (Reg), which were two kinds of information vector (IVs) were weighted to obtain the value of the contribution of each spectral variables, the influence of two IVs of Rre and Reg was considered to each spectral variable. Finally, it used the exponentially decreasing function (EDF) to remove the low contribution wavelengths so as to select the characteristic variable. In the case of near infrared spectrum of beer and corn, the prediction model based on partial least squares (PLS) was established. Compared with other variable selection methods, the research showed that AWVCPA was the best variable selection strategy in the same situation. It had 72.7% improvement compared AWVCPA-PLS with PLS and the predicted root mean square error (RMSEP) decreased from 0.5348 to 0.1457 on beer dataset. It had 64.7% improvement compared AWVCPA-PLS with PLS and the RMSEP decreased from 0.0702 to 0.0248 on corn dataset.
