最新刊期
卷 39 ， 期 12 ， 2020
- 摘要：Nanopore electrochemistry achieves the single-molecule measurement based on the electrochemically confined effect.The detection of picoampere-level current signals with milli-second duration makes a great challenge for the electrochemical instruments,which requires not only low noise and high current resolution,but also high bandwidth for capturing the rapid signals.A portable Cube ultrasensitive nanopore instrument consisting of a frequency compensation circuit,a pre-amplifier measurement system and a field programmable gate array (FPGA) based high-speed digital processing circuit has achieved the ultra sensitive electrochemical measurement with high temporal resolution,high current resolution and rapid acquisition of weak current signals.In this study,the stability of this instrument was tested by utilizing a high resistance resistor.Compared with the commercial instrument,the noise root mean square(RMS) values of the current baseline obtained with the Cube ultrasensitive nanopore instrument were reduced by 80.0%,87.5% and 48.2% under the cut-off frequencies of 5,10 and 100 kHz,respectively.Therefore,the Cube ultrasensitive nanopore instrument has a strong ability to suppress noise,offering a better current resolution.Results showed that the deviation of the applied voltage of the instrument was only 0.14% of the applied voltage change(10 mV),verifying a negligible error for the applied voltage of this Cube instrument.An Aerolysin nanopore detection of Poly(dA)4 under different applied voltages demonstrated that the error of residual current blockage was less than 0.01 when both the Cube and commercial instrument were used.Therefore,the Cube ultrasensitive nanopore instrument was suitable for the single molecule detection with high stability,high sensitivity and strong portability.关键词：nanopore;nanoelectrochemistry;single molecule detection;single molecule interface;ultrasensitive electrochemical instrumentation
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发布时间：2023-04-18 - 摘要：An analytical method was established for the determination of 118 volatile organic compounds(VOCs) in source emission by preconcentration/gas chromatography-mass spectrometry with FID detector,in combination with Deans Switch and cold oven technique.Samples were collected with a summa canister,and diluted before analysis.C2-C3 compounds were determined with FID,and quantified by external standard method.The remaining compounds were determined by mass spectrometry(MS),and quantified by internal standard method.Results showed that the calibration curves for 118 VOCs exhibited good linearity in the concentration range of 0.5-30 nmol/mol,with the correlation coefficients(r2) of 0.995 3-0.999 9.The limits of detection and the limits of quantification were in the ranges of 0.01-0.38 μg·m-3 and 0.03-1.51 μg·m-3，respectively.The average recoveries at low,medium and high spiked levels ranged from 76.4%to 110%with the relative standard deviations(RSDs,n=7) of 0.30%-6.0%.The method was applied to the determination of VOCs in the exhaust gases of mobile source(forklift) and stationary sources(shoe factory,furniture factory,printery,plastic factory and shipyard).Different degrees of VOCs pollution were detected,in which concentrations of total VOCs(TVOC) in exhaust gases from the forklift and stationary sources were 33.50-35.25 mg·m-3 and 44.54-211.71 mg·m-3,respectively.The method was simple,rapid,stable,sensitive and accurate，and was suitable for the determination of VOCs in mobile and stationary source emissions.关键词：volatile organic compounds;preconcentration;gas chromatography-mass spectrometry;source emission;summa canister
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发布时间：2023-04-18 - 摘要：In this research,a metabolomics method of ultra high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS) was developed for the detection of bile acid metabolites in serum of type 2 diabetic patients,obtaining metabolic markers and exploring potential preventive and therapeutic targets that may predict diabetes.The samples were separated on a Waters ACQUITY UPLC BEH C18 column(150 mm×2.1 mm，1.7 μm) by gradient elution with 0.05% acetic acid aqueous solution and acetonitrile as mobile phases at a flow rate of 0.40 mL/min.And then this method was used to determine the bile acid metabolites in serum of 30 diabetic patients and 50 normal persons.41 bile acid standard solutions were well isolated within 30 min.There were good linear relationships for 41 bile acids in certain concentration ranges,with their correlation coefficients(r2) of 0.986 7-0.999 7.The limits of detection(LOD) and the limits of quantitation(LOQ) were in the ranges of 0.24-7.81 nmol/L and 0.49-15.63 nmol/L,respectively.Results showed that there was a correlation between the bile acid metabolic spectra of the serum and the two groups.Through the orthogonal projections to latent structures-discriminant analysis(OPLS-DA),there are 12 kinds of bile acids,including glycoursodeoxycholic acid,glycocholic acid,taurochenodeoxycholic acid,cholic acid,ursodeoxycholic acid,glycochenodeoxycholic acid,glycodeoxycholic acid,12 ketolithocholic acid,chenodeoxycholic acid,deoxycholic acid,isolithocholic acid and lithocholic acid carrying a group of important information.Combined with the receiver operating characteristic curve(ROC curve),six bile acid metabolic markers,including taurochenodeoxycholic acid(AUC=0.68)，glycochenodeoxycholic acid(AUC=0.66),glycoursodeoxycholic acid(AUC=0.63)，cholic acid(AUC=0.63)，deoxycholic acid(AUC=0.63) and glycodeoxycholic acid(AUC=0.58) were finally obtained,which have a potential value for the early diagnosis and further research of diabetes.关键词：ultra-high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS);bile acid metabolism;type 2 diabetes mellitus;serum
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发布时间：2023-04-18 - 摘要：A two-dimensional gas chromatography-time of flight mass spectrometry(GC×GC-TOF MS) was developed for the determination of 50 substances of very high concern(SVHCs) in plastic,including 24 polycyclic aromatic hydrocarbons,17 phthalates,3 alkyl phenols,4 benzotriazole ultraviolet stabilizers,karanal and triphosphate(2-chloroethyl) ester.Samples were shattered and extracted with methanol by ultrasonic extraction.The qualitative analyses were performed by TOF MS.The quantitative analyses were performed by external standard method.Results showed that there were good linear relationships for 50 analytes in the concentration range of 0.05-15 mg/L with their correlation coefficients(r2) not less than 0.990 4.The limits of detection(LODs) and limits of quantitation(LOQs) were in the ranges of 0.04-5.96 mg/kg and 0.05-13.39 mg/kg,respectively.The recoveries at low,medium and high spiked levels ranged from 80.0% to 121% with relative standard deviations(RSDs,n=6) of 1.1%-13%.Phthalates and Polycyclic aromatic hydrocarbons were detected when this method was applied to the detection for real samples.This method could be used for the simultaneous screening and confirmation of 50 SVHCs in plastic with accuracy and efficiency.关键词：two-dimensional gas chromatography with time of flight mass spectrometry(GC×GC-TOF MS);plastic;substance of very high concern(SVHC)
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发布时间：2023-04-18 - 摘要：In this study,a novel electrochemical sensor was constructed for the detection of DNA methylation,with a DNA tetrahedral nanostructure probe(TSP) as capture probe and horseradish peroxidase-labeled IgG antibody bound to the surface of gold nanoparticles (AuNPs-IgG-HRP) as a signal molecule.After being assembled into TSP by the one step thermal denaturation method,the probe was fixed on the surface of AuNPs/AuE electrode through Au-S bond.Experienced the target DNA hybridization,5-methylcytosine (5-mc) antibody and AuNPs-IgG-HRP conjugation,the electrochemical signal was obtained by differential pulse voltammetry(DPV).The construction process of the modified electrode was characterized by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).Effects of hybridization time,5-mc antibody concentration,addition volume of IgG-HRP,concentrations of hydroquinone(HQ) and hydrogen peroxide(H2O2) on the sensor were explored.Under the optimal conditions,the biosensor exhibited a good linear response toward the methylated DNA in the range of 1.0×10-15-1.0×10-10 mol/L,with a detection limit (S/N=3) of 4.4×10-16 mol/L.The biosensor could provide a new method for the detection of DNA methylation with good selectivity and stability.关键词：DNA tetrahedral nanostructure probe;electrochemical sensor;DNA methylation;gold nanoparticles;antibody
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发布时间：2023-04-18 - 摘要：he metabolic pathways of daidzein benzene sulfonate derivatives D1-D3 in human aortic vascular smooth muscle cells were studied in this paper.The cellular metabolites of daidzein benzene sulfonate derivatives were detected by HPLC-MS to infer the metabolic pathways in vitro of benzene sulfonate derivatives preliminarily.It was found that further glucuronidation and sulfation of the hydrolytic metabolites of daidzein benzene sulfonate derivatives D1-D3 were the main metabolic pathways,and there is a competition between these two reactions.The derivatives all could be metabolized to lead compound——daidzein(DD).The benzene sulfonate group of D2 underwent hydrolysis,followed by hydrolysis of methyl ether to form DD in the metabolic pathway.It indicated that the hydrolysis of phenylsulfonate bond was easier than that of methyl ether bond under the action of intracellular hydrolase.However,there were two possible metabolic pathways for compounds D1 and D3,which showed that acetyl,ethyl and benzenesulfonate groups could be hydrolyzed simultaneously under the action of intracellular hydrolase.This study on metabolism in vitro provided a reliable theoretical basis for the overall experiment of compounds D1-D3.关键词：daidzein;benzene sulfonate;cell metabolism;glucuronidation;sulfation
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发布时间：2023-04-18 - 摘要：A detecting method for adulteration in processed meat products based on peptide markers analysis was developed in this paper,which could be performed for both qualitative and quantitative analysis.After protein extraction and trypsin digestion,the specific heat-stable peptide markers were searched in five types of meat including cattle,chicken,duck,pig and sheep,with high resolution mass spectrometry(HRMS) and bioinformatics tools.In multiple reaction monitoring(MRM) mode,these markers were further verified by high performance liquid chromatography triple quadrupole mass spectrometry(HPLC-QQQ-MS).A quantitative calibration curve was established using a meat mixture of two percentages(from 0% to 100%) with lower limit of determination of 1%.This method was used to analyze the actual samples purchased from the market.Results showed that this method is a reliable and effective strategy for meat identification,which could be used for the quantitative detection of adulteration in raw and cooked meat.关键词：peptide marker;mass spectrometry;quantitative testing;meat products;adulteration identification
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发布时间：2023-04-18 - 摘要：A validated analytical method was developed for the determination of free astragaloside Ⅳ in Astragali Radix by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).Effects of each step of pretreatment were studied on the determination of astragaloside Ⅳ in Chinese pharmacopoeia(2015)(ChP).Furthermore,impacts of n-butanol extraction and ammonia impurity removal on the determination and content variation of astragaloside Ⅳ were investigated.The differences of components caused by pretreatment were analyzed by Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR-MS).Results showed that there was a good linear relationship of the proposed method for astragaloside Ⅳ in the range of 0.387 0-2475 mg/L,with a correlation coefficient(r) of 0.999 8.The limit of detection(LOD) and limit of quantitation(LOQ) were 1.0 mg/kg and 3.0 mg/kg,respectively.The recoveries at three spiked levels ranged from 94.5% to 105%,with a relative standard deviation(RSD,n=6) of 1.4%.The relative content of astragaloside Ⅰ was the highest when Astragali Radix was directly extracted with methanol.The impurity removal process with ammonia after n-butanol extraction led to the homologues turned into astragaloside Ⅳ by hydrolysis,which significantly increased the content of astragaloside Ⅳ.Moreover,it was found that there exists a new isomer of astragaloside Ⅱ,named as neoastragaloside Ⅱ in Astragali Radix.关键词：Astragali Radix;free astragaloside Ⅳ;content change;neoastragaloside Ⅱ;ultra high performance liquid chromatography-tandem mass spectrometry
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发布时间：2023-04-18 - 摘要：As a typical reactive nitrogen species(RNS),peroxynitrite(ONOO-) plays an important role in physiological and pathological processes.In the past few years,a number of fluorescent probes have been reported in ONOO- detection.However,most of probes suffer from delayed response time,low selectivity and sensitivity,which greatly limits the real time,in situ detection of ONOO- in living organisms.Besides,some probes need complicated synthetic and purification procedures,which restricts their promotion and application.In this work,a novel benzothiazole-based fluorescent probe(E)-2-(benzo［d］thiazol-2-yl)-6-((2,2-dimethylhydrazono)-methyl)-4-methylphenol(BD) for ONOO- detection was prepared through the condensation reaction of 2-(2′-hydroxy-3′-aldehyde-5′-methylphenyl)benzothiazole and 1,1 dimethylhydrazine.The free probe showed weak fluorescence due to the nonradiative deactivation induced by the rotation of N—N single bond.Upon treatment with ONOO-,the hydrazone in the probe BD was hydrolyzed into aldehyde group,and thus the N—N single bond was removed,which resulted in a dramatic fluorescence enhancement with naked eye colorimetric and fluorescence color changes.The sensing mechanism of probe BD for ONOO- was verified by high resolution mass spectrometry.In PBS buffer solution(DMSO∶H2O=2∶8,by volume,pH 7.4),the probe exhibited many advantages,including rapid response(25 s),low detection limit(7 nmol/L),high selectivity to ONOO- over other biological related species and tolerance of a wide range of pH values including physiological pH.More importantly,this probe was successfully applied to the fluorescence imaging of ONOO- in HepG2 cells with excellent cell-membrane permeability.Therefore,it could be used as a potential analytical tool to reveal the role of ONOO- in living cells.关键词：peroxynitrite;fluorescent probe;benzothiazole;cell imaging
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发布时间：2023-04-18 - 摘要：An analytical method for the metabolomics of Lonicera japonica was established based on liquid chromatography-mass spectrometry(LC-MS).The extraction solution was optimized as a mixture solution of methanol and water(3∶1,by volume).The repeatability and precision of the method were investigated.It was found that the method could meet the requirements for metabolomics analysis with good stability.The primary and secondary metabolites in Lonicera japonica were identified by accurate mass,retention time and MS/MS data.A total of 157 metabolites were identified,including amino acids,nucleosides,fatty acids,lipids,phenolic acids,flavonoids and iridoid glycosides,etc.According to the metabolomics analysis of Lonicera japonica in different flowering stages,it was found that the secondary metabolites of phenolic acid,flavonoids and iridoid glycosides decreased significantly with the process of flowering stages.For the primary metabolites,the contents of most amino acids,nucleosides and oxidized fatty acids decreased significantly,while the contents of most Lyso PC,Lyso PE and fatty acids increased significantly.The results obtained provide theoretical guidances for study on the metabolic mechanism of medicinal components and the late planting and harvesting of Lonicera japonica.关键词：Lonicera japonica;metabolomics;liquid chromatography-mass spectrometry(LC-MS);primary metabolites;secondary metabolites;flowering stages
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发布时间：2023-04-18 - 摘要：In this paper,an electrochemical immunosensor for the detection of bisphenol A(BPA) was constructed,based on the preparation of a poly-L-lysine/nano-gold modified electrode by electrodeposition,with disposable screen printed carbon electrode as the substrate.Results showed that,when the dilution factors for the antigen and the primary antibody were 1 000 times,the incubation time for the primary antibody was 60 min,and the pH value for the electrochemical detection environment was 7.4,there existed a good linear relationship between reduction peak current and BPA in the concentration range of 1-250 ng/mL,with a correlation coefficient(r2) of 0.993 and a detection limit of 0.85 ng/mL.With good specificity,reproducibility and stability,this method was applied in the detection of BPA in samples with spiked recoveries of 983%-104%,indicating that the BPA immunosensor has an application potential in the detection of bisphenol A in actual water samples.关键词：nano-gold;poly-L-lysine;screen printed carbon electrode(SPCE);immunosensor;bisphenol A(BPA)
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发布时间：2023-04-18 - 摘要：A ‘signal-off’ electrochemical immunosensor was designed for the ultra-sensitive detection of α-fetoprotein(AFP） based on the synergistic catalytic enhancement of metallic nano mimic enzyme to produce insoluble precipitation.The hollow gold-palladium-platinum nanoparticle bioconjugates(HAuNPs-PtPdNPs-Ab2） were immobilized on the electrode modified with electroactive substance nickel hexacyanoferrate nanoparticles through sandwich type immunoassay.In the presence of H2O2,HAuNPs and PtPdNPs as peroxidase-mimicking enzymes catalyzed 4-chloro-1-naphthol(4-CN） to generate insoluble and non-conductive precipitation benzo-4-chlorohexadienone(4-CD） at the electrode interface,thus effectively increasing the hindrance of electron transfer and leading to a significant decrease in electrochemical signal.The quantitative detection of AFP was achieved by the changes of electrochemical signal before and after the addition of AFP.Under the optimized reaction conditions,the experiment proved that the established immunosensor possessed a wider dynamic response from 0.1 pg/mL to 200 ng/mL in the detection of AFP with a low detection limit of 33 fg/mL.On the basis of the synergistic catalytic amplification,the proposed strategy could provide an effective method for multiple signal amplification to enormously improve the sensitivity of the biosensor.关键词：synergistic catalytic effect;electrochemical immunosensor;metallic nanoparticle;mimic enzyme
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发布时间：2023-04-18 - 摘要：An ultra high performance liquid chromatography-quadrupole-time of flight mass spectrometry(UHPLC-QTOF MS/MS) was established for the simultaneous determination of 4 kinds of new psychoactive substances of cathinone in blood samples,including 1-(3,4-methylenedioxyphenyl)-2-methylaminopropan-1-one(methylone),1-(3,4-methylenedioxyphenyl)-2 ethylaminopropan 1-one(ethylone),1-(4-chlorophenyl)-2-methylaminopropan-1-one(4 CMC) and 1-(4-chlorophenyl)-2-ethylaminopropan-1-one(4-CEC).0.5 mL blood sample was mixed with water and acetonitrile by a volume ratio of 5∶2∶13,vortex oscillated for 1 min,and centrifuged at 12 000 r/min for 15 min to precipitate the protein.The supernatant was separated on an Acquity UPLC-BEH C18 column(2.1 mm×100 mm,1.7 μm),with 0.1% formic acid-water(5 mmol/L ammonium acetate) and acetonitrile as mobile phases by gradient elution,and detected in positive ion［M+H］+ scanning under multiple reaction monitoring(MRM) mode.Results showed that there were good linear relationships for four target drugs in the concentration range of 5-500 ng/mL,with the limits of detection and limits of quantitation of 2 ng/mL and 5 ng/mL,respectively.The recoveries ranged from 87.3% to 111% with the intra day precision and inter day precision not more than 8.1% and 8.6%,respectively.The method could be used for the simultaneous detection of 4 new psychoactive substances of cathinone in blood samples to meet the needs of actual inspection work.关键词：ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(UHPLC-QTOF MS/MS);new psychoactive substances of cathinone;precipitated protein;blood sample
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发布时间：2023-04-18 - 摘要：A “turn-on-off” type fluorescent probe based on terbium coordination polymers was prepared for the detection of trace mercury ions.The terbium coordination polymers were prepared with terbium ions as luminescence center and guanyl 5 disodium phosphate(GMP） as ligand,which could emit green fluorescence.The intensity of the luminescence was increased with the addition of ct-DNA,and a “turn-on” type of fluorescent probe was formed.Then,the “turn-on-off” type fluorescent probe was formed by quenching the fluorescence with the interaction between the heavy metal mercury ions and ct-DNA and ligand of GMP with the addition of mercury ions.The calibration curve for mercury ions was linear in the range of 50-1 200 μg·L-1 ,with a correlation coefficient(r2） of 0.991 5 and a regression equation of(I0-I）/I0=0.000 2 C+0.010 7.The limit of detection was 1.5 μg·L-1,while the relative standard deviation(RSD） was 2.3%(C=600 μg·L-1,n=5）.The probe was applied to the detection of trace mercury ions in river water with recoveries of 98.1%-99.8%and RSD of 0.28%-1.9%.关键词：lanthanide coordination polymers;ct-DNA;terbiumion;fluorescence spectroscopy;mercury ion
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发布时间：2023-04-18 - 摘要：A high performance liquid chromatography(HPLC) using fused-core silica particles column was developed for the rapid determination 16 local anesthetic components,including procaine,tetracaine,methyl isoeugenol,chloroprocaine hydrochloride,lidocaine hydrochloride,benzocaine,ropivacaine mesylate,butacaine sulphate,procainamide,prilocaine,bupivacaine,benoxinate hydrochloride,eugenol,pramoxine hydrochloride,cinchocaine and methyl eugenol.The samples were ultrasonically extracted with 0.1%hydrochloride-methanol,and separated on an Agilent Poroshell 120 EC-C18(50 mm×4.6 mm×2.7 μm) at 35 ℃ by gradient elution,with dipotassium hydrogen phosphate solution(pH 3.0)-methanol-acetonitrile as mobile phase at a flow rate of 1.5 mL/min.The detection wavelengths for diode array detector were set at 210 nm and 280 nm.Quantification analysis was performed by the external standard method.Results indicated that the calibration curves for the 16 compounds showed good linearity in a certain range of mass concentration with their correlation coefficients not less than 0.999 7.The limits of detection(LOD,S/N=3) and limits of quantitation(LOQ,S/N=10) for ropivacaine mesylate were 3.1 μg/g and 10.2 μg/g,respectively.The LODs and LOQs for other 15 compounds were 1.0 μg/g and 3.3 μg/g,respectively.The average recoveries at three spiked levels ranged from 93.3%to 103%,with relative standard deviations(RSD) of 0.08%-1.2%.The method was rapid and accurate,and could be used for the rapid screening of local anesthetic components in adult products,indicating its extensive application prospect.关键词：rapid screening;high performance liquid chromatography(HPLC);adult products;local anesthetic components
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发布时间：2023-04-18 - 摘要：In this study,a gas chromatography-mass spectrometry(GC-MS) was developed for the simultaneous detection of 13 kinds of organophosphate esters(OPEs) in greenhouse soil,including triethyl phosphate,tripropyl phosphate,tri-n-butyl phosphate,triisobutyl phosphate,tributoxyethyl phosphate,tris(2-ethylhexyl) phosphate,tris(2-chloroethyl) phosphate,tris(1-chloro-2-propyl) phosphate,Tris(1,3-dichloro-2-propyl) phosphate,triphenyl phosphate,tricresyl phosphate,toluene diphenyl phosphate and 2-ethylhexyl diphenyl phosphate.The experimental parameters such as extraction solvents,extraction methods,extraction times,extraction column types and chromatographic conditions were optimized.The soil samples were ultrasonically extracted with n hexane-acetone(1∶1,by volume),and then purified with a Florisil solid phase extraction column,followed by analysis of GC-MS in selected ion monitoring mode and quantitative analysis by internal standard method.Results showed that there were good linear relationships for 13 target compounds in the mass concentration range of 1-500 μg/L,with their correlation coefficients(r2) of 0.999 3-0.999 7.The limits of detection(LODs,S/N=3) and limits of quantitation(LOQs,S/N=10) were in the ranges of 0.04-2.31 μg/L and 0.13-7.69 μg/L,respectively.The soil spiked recoveries at three spiked levels of 1.0,10 and 50 μg/L ranged from 54.5% to 130%,with relative standard deviations(RSDs) of 1.7%-9.9%.This method was applied to the analysis of 41 soil samples from vegetable greenhouses in Beijing.Except for tripropyl phosphate,12 kinds of OPEs were detected in all samples,with the concentration range of 1.90-632 ng/g(dry weight,dw),the mean value of 87.8 ng/g and the median value of 39.7 ng/g.Tributyloxyethyl phosphate is the most abundant OPEs,contributing about 20% of the total content of 12 kinds of organophosphate esters(∑12OPEs).This method is simple,rapid,sensitive and accurate,and could meet the demands for analysis of 13 OPEs in soil.关键词：ultrasonic extraction;gas chromatography-mass spectrometry(GC-MS);organophosphate esters;greenhouse soil
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发布时间：2023-04-18 - 摘要：In this paper,a simple and highly sensitive colorimetric probe was constructed for the determination of melatonin based on the etching of spherical Ag nanoparticles(AgNPs) by HAuCl4.The AgNPs could be oxidized and etched into Ag+ by HAuCl4,and the reduced Au was deposited on the surface of the etched AgNPs,resulting in the decrease of absorbance and the variation of solution color from yellow to orange.However,in the presence of melatonin,HAuCl4 was reduced by melatonin,inhibiting the etching of AgNPs,and resulting in an increase in absorbance and a decrease in color.Results showed that there existed a good linear relationship between the change values of absorbance(ΔA) and the logarithm values of melatonin concentration(lgC) in the range of 0.1 nmol/L-1.0 mmol/L,with a linear equation of ΔA=0.049 8+0.516lgC,a correlation coefficient(R2) of 0.996 4 and a detection limit of 0.09 nmol/L.This method was successfully applied to the determination of melatonin in human urine and grape with satisfactory results.关键词：spherical Ag nanoparticles;colorimetry;oxidation etching;melatonin
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发布时间：2023-04-18 - 摘要：Drug abuse is a global problem,posing a major threat to peoples physical and mental health,economic development and social progress.Drug inspection is a key measure to ensure public security and social order,calling for development of sensitive and accurate analytical techniques.In recent years,new psychoactive substances such as fentanyl compounds have been spreading rapidly due to their stronger effects of excitement,hallucinations and anesthesia,which have become the third generation drugs after traditional drugs and synthetic drugs.The abuse of fentanyl drugs has caused a large number of deaths and serious social problems.In this regard,the authorities worldwide have attached great importance to formulating laws and regulations for their control,and researchers have developed a variety of analytical techniques.In this paper,the advances in traditional laboratory analytical techniques and rapid on site analytical techniques were summarized,and the development trend and application prospects were discussed,which may provide some technical instructions for the researchers in related fields.关键词：fentanyl;new psychoactive substances;analytical techniques;review
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发布时间：2023-04-18 - 摘要：Rolling circle amplification(RCA) is an isothermal nucleic acid amplification technique.Due to its high efficiency and high fidelity,this technique has been widely used in biosensors.This review introduces the principle of RCA technique,the common cyclization types of RCA template and the common types of RCA,as well as the fluorescent,colorimetric and electrochemical biosensors based on RCA.The aim of this review is to provide references for the further development and application of the RCA technique in biosensors.关键词：isothermal nucleic acid amplification;rolling circle amplification;biosensor
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发布时间：2023-04-18 - 摘要：In this paper,optical and electrochemical detection techniques based on biochemical detection of smartphones and their powerful communication means in biochemical sensor analysis are reviewed.Specifically,the performance,advantages and applications of biochemical sensor technology integrated with smartphones in biochemical detection are mainly introduced.Meanwhile,the current limitations and challenges of smartphones in biochemical sensor analysis are discussed.Finally,the future development direction and potential opportunities are also looked forward to.关键词：smartphone;optical sensors;electrochemical sensor;wireless communication;biochemical analysis
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发布时间：2023-04-18
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