最新刊期
卷 40 ， 期 6 ， 2021
- 摘要：Accurate measurement of flame temperature is always an important research topic,which is significant for the establishment of combustion models,exploration of atomization mechanisms,combustion reaction mechanisms and reduction of pollutants emissions during combustion processes,etc.Non-contact flame temperature measurement method is a preferred important flame diagnostic technique on account of scarcely any disturb on combustion regime,and atomic spectroscopy-based techniques have drawn wide attention and been widely applied in the field of high temperature diagnosis because of their inherent non-contact characteristics.Atomic spectroscopy methods play an important role in non-contact methods because of the features of single spectrum,strong spectral signal and user-friendly operation.The main principle of atomic spectroscopy methods is that atoms occupy on different energy levels which obey Boltzmann distribution under thermodynamic equilibrium and thus flame temperature could be obtained from corresponding atomic spectrum signals’ ratio.According to the distinctions of utilized spectra,atomic spectroscopy methods could be divided into three categories,i-e.,atomic absorption spectroscopy method,atomic emission spectroscopy method,and atomic fluorescence spectroscopy method.The correlative principles,development and application of the atomic spectroscopy methods,including two-line atomic absorption spectroscopy method,two-line atomic emission spectroscopy method,Boltzmann plot method and two-line atomic fluorescence spectroscopy method are simply summarized in this review.关键词：flame temperature measurement;non-contact measurement;atomic absorption spectroscopy;atomic emission spectroscopy;atomic fluorescence spectroscopy;review
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发布时间：2023-04-18 - 摘要：There are a lot of studies about nanocrystal of lead halide perovskites(LHPNCs) reported,which have received a widespread concern in photovoltaics and optoelectronics due to their excellent characteristics in high molar absorbance coefficient,high crystal defect tolerance,ultra-fast carrier mobility and their narrow full width at half maximum，even their excellent optoelectronic characteristics make them also attractive in sensing fields.In the past few years,many review articles have successively been published on the synthesis,stability improvement and applications of LHPNCs in solar cells,LEDs,lasers and catalysis,etc.However,reviews focusing on the sensing applications of LHPNCs,including an overview of LHP NCs in electrochemiluminescence(ECL),are still absent.The ECL studies and applications of LHP NPs are summarized in this review.The remaining challenges and perspectives are discussed to promote the future development of LHP NPs related ECL studies.It is believed that this review will provide readers with the current status and future development of LHP NPs in the ECL studies.关键词：lead halide perovskites;electrochemiluminescence;sensing
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发布时间：2023-04-18 - 摘要：The key factor to improve the sensitivity and accuracy of biosensing is to select suitable target recognition molecules.Currently,antibodies,aptamers,peptides and antibiotics are regarded as the most frequently used target recognition molecules.However,the molecules mentioned above have a certain limitations.For instance,antibodies and aptamers suffer from high production cost and difficulties for long-term storage,whereas peptides,antibiotics have a relatively low specificity towards the analyte.Therefore,it is necessary to find more superior substitutes.M13 phage is a type of flexible filamentous bacteriophage which could specifically infect E.coli with F factor.Due to its simple component and clear genetic background,M13 phage becomes one of the bacteriophages with earliest research history.M13 phage is the bacteriophage used by the 2018-Nobel Prize winner-George Smith to develop the phage display technology.By using phage display technology,the foreign peptide,protein or antibodies could be fused and coexpressed on the capsid protein surface of M13 phage,while by constructing phage display peptide library with phages that display various types of peptide and using biopanning technique,peptides with high specificity towards target analyte could be obtained.Up till now,thousands of highly specific peptides have been selected by biopanning from various phage display peptide libraries,and their affinities towards the target analytes are comparable to those of antibodies.Under this circumstance,M13 phage with targeting peptide has attracted the researchers’ interest in the field of analytical chemistry,and has become a novel platform for the construction of biosensing analysis.M13 phage consists of up to 2 700 copies of primary capsid protein pVIII wrapped in a helical form around the inner ssDNA and 3-5 copies of minor capsid proteins pVII,pIX,and pIII,pVI at both ends.This structure not only endows it good chemical stability,but also enables it to be functionalized by phage display technology or chemical modification.By coupling with appropriate signal output,M13 phages could be used for biosensing.In fact,M13 phages are an ideal platform to conduct signal simplification:by displaying/modifying the 3-5 copies of minor capsid proteins pIII with target recognition peptide and modifying the 2 700 copies of primary capsid protein pVIII with signal probes,one target-binding event can trigger a (3-5):2 700-fold signal amplification in theory.M13 phages with target recognition peptide on their pIII protein could be obtained by biopanning from phage display peptide library or by phage display techniques,whereas the signal probes reported so far include AuNPs,AgNPs,fluorescent dyes,SERS probes,etc.The detection methods coupled with M13 phages-based sensing platform include colorimetric method,fluorescent method,SPR detection,electrochemical sensing and quartz crystal microbalance method,etc.M13 phages could be applied not only for the sensing for microbes,metal ions,biomarkers and cells,but also used for the bioimaging of tumor cells and bacteria.Although great achievements have been obtained based on M13 phages,the M13 phages based biosensing still has some limitations,for example,due to the technique limitation,large proteins still cannot be displayed on the M13 phages surfaces,the mechanism for the interaction between target analyte and M13 phages needs further exploration.Nevertheless,the application prospect of M13 phages in the field of analytical chemistry is still promising.In this review,the structures of M13 phages,phage display technology and their application in the fields of optical sensing,electrochemical sensing,quartz crystal microbalance sensing and imaging analysis have been summarized.The development trend for the application of M13 phages in analysis is also prospected.关键词：M13 phage;phage display;analysis;biosensing
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发布时间：2023-04-18 - 摘要：Biosensing platform is one of the branches of chemical sensing platform,which is sensitive to the biomolecules and can convert the concentration changes of biomolecules into electric signal for the sensing purpose.Among the various biosensing platforms,fluorescent nano-biosensing platforms have attracted widely attention due to their advantages of high sensitivity,good selectivity,operational simplicity,low cost,real-time monitoring,etc.In recent years,with the rapid development of nanotechnology,nanostructured materials(nanomaterials) exhibit some special advantages in the field of biosensing.Compared with the traditional materials,nanomaterials exhibit unique physical and chemical properties,such as optical,electrical,mechanical,catalytic and magnetic properties.As a novel type of multifunctional nanomaterials in nanoscience and nanotechnology,metal(e-g.,Au,Ag,Cu,and their alloys) nanoclusters(MNCs) are typically composed of several to dozens of metal atoms whose core sizes are usually below 2 nm.Benefiting from their unique properties of strong photoluminescence,facile preparation and surface functionalization,excellent biocompatibility,ultra-small size and low toxicity,MNCs have been applied in many fields such as energy catalysis,medical treatment,electronic devices and biosensing.Especially,they have extremely outstanding fluorescent properties of large Stokes shift,tunable fluorescence emission,high optical stability and fluorescence quantum yield,compared with the traditional fluorescent organic dyes,proteins,quantum dots and other fluorescent materials.Based on the above properties,MNCs have been widely used as fluorescent nanoprobes in the field of biosensing.In this review,the latest development of MNCs based fluorescent nano-biosensing platforms on the basis of various construction mechanisms were presented.The applications of MNCs in the field of sensing ions,biomolecules,pH and temperature were introduced.It is believed that this review could provide some novel insights and theoretical guidance to construct more prospective biosensors based on different designed sensing mechanisms.关键词：fluorescent nanoprobe;metal nanoclusters;biosensing;nanomaterial
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发布时间：2023-04-18 - 摘要：Optical bio-sensing is a kind of microanalysis technology based on the generation of various optical signals.It has the advantages of simple operation, low detection cost, strong anti-interference ability and in situ detection.It has a broad application prospect in clinical diagnosis, drug analysis, environmental monitoring and other fields.Meanwhile, gold nanoparticles(AuNPs), as a particularly important class of nanomaterials, have been widely used in the construction of optical bio-sensing methods due to their unique optical properties.In this review, the recent progresses of AuNPs-based optical bio-sensing methods are summarized, the possible problems in practical application are proposed, and the future development trend is prospected.关键词：gold nanoparticles;optical bio-sensing methods;detection;review
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发布时间：2023-04-18 - 摘要：Liquid crystal(LC) biosensors develop based on highly sensitive responses of LC to interfacial properties and its inherent optical anisotropy,which show extraordinary application value in detecting and analyzing of biological samples.By decorating with a stimuli-responsive molecule,LC interface can sensitively respond to the presence of biological analytes,which directs the orientation of LC molecules at the LC interface.Further,the short-range interaction occurred at the LC interface can change the orientation of bulk LC phase and lead to a visual transfiguration through a polarized optical microscope(POM).LC biosensors does not need to label the target analyte,and easily transforms molecular events into detectable optical signals with a simple optical instrument.Because of the advantages of simplicity,sensitivity,efficiency,rapidity and low cost,LC biosensors have been widely used in the field of bioanalysis.Herein,this article briefly reviews the recent advances in LC biosensors for the analysis of small biomolecules,biomacromolecules and organism.In particular,we discuss the development and challenge of the emerging area where the LC biosensor is introduced to a microfluidic cell chip.LC biosensors have been successfully applied to cell analysis with complex and diverse interfacial phenomena.In the future,the design and usability of LC sensors in the simulated cell microenvironment need to be further studied.关键词：liquid crystal(LC);biosensing;cell analysis;microfluidics;cell microenvironment
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发布时间：2023-04-18 - 摘要：Plasmonic nanoparticles(PNPs) have been widely used in the fields of biochemical sensing,bioimaging,disease diagnosis,cancer therapy and materials science,etc due to their advantages of small size,easy surface modification,good biocompatibility and low toxicity.The light-scattering optical properties of plasmonic nanoparticles could be controllably adjusted by tuning their size,composition,morphology and microenvironment,which could be developed for biochemical and pharmaceutical analysis.In addition,with the help of unique local surface plasmon resonance(LSPR) characteristics of plasmonic nanoparticles,a single-particle light scattering microscopy equiped with high spatial resolution and sensitivity could be used to obtain real-time image at a single particle level.Then,a variety of microscopic imaging analysis methods have been developed according to the signal variation resulting from changes of the size,composition,morphology,microenvironment or coupling,which could be mainly classified into four kinds of methods,including wavelength shift of scattering spectrum,change of single-particle scattering intensity,high-throughput RGB analysis and counting method.The method based on the change of wavelength shift of nanoparticles LSPR scattering spectra is accurate and sensitive,but it requires an expensive single-particle scattering spectrophotometer and a complex operation.The method based on the change of scattering intensity is simple and feasible,but it is easily affected by various factors such as the nanoparticles size and exposure time.High-throughput RGB analysis method has high accuracy and low cost,but it is not applicable for the analysis of single particle whose color change is not obvious,and whats more the reproducibility of this method is poor.The method of single particle counting is highly sensitive,but sometimes the particle will not distribute evenly and the interference coming from the background impurities limits the accuracy of the method.Therefore,these four quantitative methods have their own advantages and disadvantages.In addition,some new quantitative methods have been gradually developed in recent years.For example,the researchers have developed new quantitative methods for time-resolved analysis,combining the dark field microscopy with optical devices such as polarizers and filters to eliminate background interference,as well as instruments such as electrochemistry and Raman to expand the scope of application.Furthermore,in order to improve the accuracy and sensitivity of analytical methods,combinations of the dark-field microscopy with some modern computer science technologies,such as deep learning,cloud computing and artificial intelligence,have become more and more popular.Based on the above reasons,this mini review focuses on the application of single-particle light scattering microscopy in the field of biochemical and pharmaceutical analysis,then the recent new research progress is summarized,and several main quantitative methods of single-particle light scattering microscopy in quantitative analysis are discussed,and finally their future development trends are put forward.It is expected that the review could provide a certain academic reference for the new comer.关键词：plasmonic nanoparticles;dark-field imaging;single particle spectroscopy;counting method;RGB color analysis
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发布时间：2023-04-18 - 摘要：Gel permeation chromatography(GPC) is a separation technology developed in the 1960s,which has the advantages of low requirements for mobile phase,mild experimental conditions,high reproducibility,rapid analysis and high solute recovery,etc.As a kind of liquid separation chromatography,gel permeation chromatography has a unique separation effect,it has been rapidly developed and widely used in many fields such as petrochemical engineering,biomedicine,food hygiene,environmental monitoring,etc.Progresses in the synthesis,performance and application of column fillers for gel permeation chromatography such as polyacrylamide gel and polystyrene gel in recent years are reviewed in this article,and the new fillers,as well as their application fields and prospects are also introduced.关键词：gel permeation chromatography;column fillers;liquid chromatography
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发布时间：2023-04-18 -
Research on Tumor Marker Determination Methods Based on Inductively Coupled Plasma Mass Spectrometry
摘要：Cancer is a leading cause of death and a severe impediment to increasing life expectancy.According to Global Cancer Statistics 2020,there are an estimation of 19.3 million new cancer cases and 10 million cancer deaths worldwide in 2020.Early diagnosis and treatment are crucial to reducing cancer mortality.Tumor markers are the metabolic and immune molecules produced by tumor cells or tumor-related normal tissues.The concentration of tumor marker will change abnormally with the tumor occurrence,metastasis and treatment.Tumor marker detection is of great significance for cancer's early diagnosis,progress monitoring,and prognosis.Carcinoembryonic antigen(CEA) is a broad-spectrum tumor marker related to colorectal cancer,pancreatic cancer,liver cancer,lung cancer,breast cancer and ovarian cancer.Prostate-specific antigen(PSA) monitoring in serum effectively diagnoses whether prostate cancer has recurred after surgery.Ultrasonography combined with alpha-fetoprotein(AFP) detection could effectively screen and diagnose hepatocellular carcinoma(HCC) for high-risk patients.But most importantly,inductively coupled plasma mass spectrometry(ICP-MS) is an analytical method with high resolution,high sensitivity,wide dynamic range(9 orders of magnitude) and multi-element simultaneous detection.In the past two decades,ICP-MS methods based on stable isotope labels have been widely used to detect metal ions,nucleic acids,peptides,proteins,enzymes,small molecules and single cells.Currently,ICP-MS methods for tumor markers detection have also been widely reported.In this review,according to distinct interactions,ICP-MS methods are divided into two types:immunoassay methods and nucleic acid-based methods.The construction and application of each are discussed in the subsequent section.In the third part,common tumor markers and related cancer types are summarized in a table.CEA,PSA,AFP,and their ICP-MS detection methods are described in detail,along with the separation method of excess tags and the signal amplification mechanism of nanoparticle tags are discussed.Besides,only one tumor marker detection may get a false-positive result.Multiple detection could effectively reduce the false positive rate and improve the specificity of diagnosis.This approach's advantage lies in reducing sample consumption,shortening experiment time,and improving diagnostic accuracy.Thus,multiple detection has attracted widespread attention.Combined with laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS) and flow cytometry mass spectrometry,it is possible to simultaneously determine multiple proteins on a single microarray spot,cell,and cancer tissue.Multiple biomarkers detection based on ICP-MS is briefly described,and the challenge of constructing multiple detection methods is also discussed in this review.Finally,limitations of ICP-MS detection methods based on element labeling are discussed.Anticipated developments in ICP-MS detection are proposed,including:①Development of new strategies,②Combination with other technologies such as big data analysis,③Transformation of laboratory research results into clinical application technologies.关键词：metal stable isotope;bioassay;inductively coupled plasma mass spectrometry;tumor marker;review- 3
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发布时间：2023-04-18 - 摘要：Lipids play a crucial role in cells and organisms by acting as the key components of cell membranes,the sources for chemical-energy storage and the messengers for cellular signaling,etc.It is generally believed that the physiological processes of cells highly rely on the chemical complexity and structural diversity of lipid compounds.In addition,the progression of many diseases such as diabetes,atherosclerosis,neurodegenerative diseases and tumorigenesis might be also related to the dysregulated lipid metabolism.Therefore,the precise structural characterization of lipids plays a vital role in exploring their biological functions.Mass spectrometry(MS) is the first choice for lipid analysis and lipidomics investigation due to its merits of high sensitivity,good specificity and informative,etc.,while the advent of ambient ionization MS provides an important tool for in situ,real-time,direct and rapid analysis for lipids and lipidomics investigation under ambient and open-air conditions,facilitating the in-depth investigation on the roles and mechanisms that lipids play in organisms.With the continual development of ambient ionization MS techniques in lipid analysis and lipidomics,it is of great importance to comprehensively characterize the structures.The recent progresses in high-resolution MS(e-g-,orbitrap MS and fourier transform ion cyclotron resonance MS) and tandem MS techniques have substantially promoted the development of lipid analysis and lipidomics investigation by ambient ionization MS.High-resolution MS provides the ability to obtain molecular formulas by accurate mass measurements,while tandem MS enables the detailed structural composition of the fatty acyl chain and head group of a mass-selected lipid ion via collision-induced dissociation(CID) or high-energy collision dissociation(HCD).In spite of this,the full structural identification of lipid species remains challenging.Unsaturated lipids are a series of lipid species containing one or more carbon carbon double bond(C‖C) in their fatty acyl chains.The locations of C‖C might have remarkable effects on their biological functions,and even could serve as the biomarkers of disease pathology.However,conventional tandem mass spectrometry techniques such as CID and HCD are unable to provide the molecular information for precise location of C‖C bonds.To address these problems,scientists have spent great effort on incorporated derivatization and ion activation/dissociation methods in ambient ionization MS to achieve the precise structural elucidation on lipid C‖C locations in an isomer.The typical derivatization and ion activation/dissociation methods that have been successfully applied in ambient MS include Paternò-Büchi(PB) reaction,epoxidation,ozoneinduced dissociation(OzID) and ultraviolet photodissociation(UVPD).In this article,the ambient MS techniques based on PB reaction,epoxidation,OzID,UVPD are described in detail,and the applications of these techniques in accurate identification of lipid C‖C location and isomer differentiation are also discussed.The development trends of ambient MS in precise structural analysis of lipids are also prospected.关键词：ambient mass spectrometry;chemical derivatization;ion activation;lipids;structural characterization;review
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发布时间：2023-04-18 - 摘要：Phosphorus is one of the essential nutrients for living things.However,in surface water and near shore seawater,total phosphorus has been the main pollution index due to the influence of human activities.Total phosphorus determination could generally be performed in two steps,namely various forms of phosphorus in water samples are firstly digested into orthophosphates,then determined by one of the detection methods.The digestion methods include sulfuric acid-nitric acid digestion,dry graying digestion,microwave assisted digestion,digestion with potassium persulphate and high temperature/pressure and UV photo-oxidation,while the detection methods contain electrochemical method,chemiluminescence method,phosphomolybdenum blue method and vanadomolybdophosphoric method.Currently,digestion with potassium persulphate and high temperature/pressure and detection with phosphomolybdenum blue are most widely used.Meanwhile,instruments for total phosphorus determination are developed based on the digestion and detection methods mentioned above,which are mainly divided in two types,i-e.,one type used in laboratory for water sample off-line analysis and the other used in the field for water body on-line monitoring.The research progresses of the above-mentioned analytical methods and instruments for total phosphorus in environmental water samples and water bodies in the past twenty years are summarized in this review.The characteristics of each method and analytical instrument are stated and compared,and the developing trends of the analysis methods and analytical instruments for total phosphorus are prospected.关键词：total phosphorus;review;environmental water sample;digestion;determination method;analytical instrument
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发布时间：2023-04-18 - 摘要：Antibiotic resistance genes(ARGs) may cause serious threat to public health,which are regarded as an emerging contaminant.Their presence and propagation in aquatic environment have attracted great attention.Increasing studies show that intracellular ARGs and extracellular ARGs exhibit different distribution patterns and environmental behaviours.It is necessary to investigate their pollution statuses for a comprehensive understanding of ARGs propagation in aquatic environment.The mechanisms of five common microbial DNA extraction methods and their applications in the detection of intracellular and extracellular ARGs in water samples are summarized in this study.The contamination status and migration propagation characteristics of intracellular and extracellular ARGs in three typical aquatic environments,i-e.sewage system,surface fresh water system and marine system are compared.The basic information regarding the technological means and pollution status of ARGs pollution in aquatic environment is provided in this review,which is of great significance for the control of ARGs in aquatic environment.关键词：intracellular antibiotic resistance genes;extracellular antibiotic resistance genes;DNA extraction;migration and transformation;aquatic environment
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发布时间：2023-04-18 - 摘要：Pharmaceuticals and personal care products(PPCPs) have received increasing attention due to their large amount of usage throughout the world as well as the comparable quantities introduced into the environment with “priority” pollutants.Meanwhile,gadolinium-based contrast agents(GBCAs) might belong to this class of chemicals.As a result of high doses of GBCAs administered in magnetic resonance imaging(MRI) exams,their unmetabolized excretion,and insufficient removal in wastewater treatment plants(WWTPs),large amounts of GBCAs are released into environment.Some of them have shown potential physiological toxicity and neurotoxicity.In this paper,the characteristics,exact classification,current environmental situation,and the analysis methods of GBCAs are reviewed,which might provide a reference for the risk assessment on GBCAs in the future.关键词：pharmaceuticals and personal care products(PPCPs);gadolinium-based contrast agents(GBCAs);analytical methods;current environmental situation;toxicity
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发布时间：2023-04-18 - 摘要：It's of great significance to develop efficient sampling and analytical techniques for tobacco volatile organic compounds(VOCs) as the tobacco VOCs from complicated tobacco matrix are usually at low content with complex composition and high volatility.The recent progresses on the separation or enrichment media such as graphene composite material,silicon-based material,and magnetic extraction sorbent,etc.,as well as related sampling techniques for tobacco VOCs,including QuEChERS,solid phase microextraction and liquid phase microextraction,etc.,are reviewed in this paper.Meanwhile,the corresponding applications of analytical techniques for tobacco VOCs in terms of quality control,etc.are also summarized.Finally,the future research trend of this field is prospected in this paper.关键词：tobacco;volatile organic compounds;sample preparation;enrichment medium;sampling technology;analytical application
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发布时间：2023-04-18 - 摘要：Cyclic chemiluminescence is a novel method.With a continuous success in experimental research,this method has been showing many unexpected applications,but its theoretical research is still waiting for breakthrough.Herein presented is the theoretical deduction on the cyclic chemiluminescence of luminol system sensitized by cobalt chiral complexes,based on the reaction mechanism of single electron transfer.The resulting theoretical formulas could stand the test of some literature data,which are able to figure out the theoretical meaning of the data.In addition,some of the theoretical formulas were also derived that were not very compatible with the literature speculation but could stand the test of some experimental data presently available.According to the obtained formulas,it is also able to deduce some new detection methods of cyclic chemiluminescence.This may contribute to the further researches and applications of this method.关键词：cyclic chemiluminescence;theory;intensity change of luminescence peak;determination of reaction kinetic constant;experimental verification
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发布时间：2023-04-18 - 摘要：Problems of heavy-metal pollution have been drawing more and more attraction of all parts of society.To establish a simple,rapid,stable and efficient detection method for heavy metal ions is an urgent need for environmental stability and life-health.The copper ions(Cu(Ⅱ)) may be an important factor leading to several diseases,including Alzheimer's disease,prion disease and amyotrophic lateral sclerosis.Although some significant researches have been reported in development of chemosensors to detect Cu(Ⅱ),the development of peptide-based fluorescent chemosensors capable of detecting multiple ions has received considerably less attention.The metalloprotein database offers a great possibility for the design and screening of sensing elements in metal ions detection.Through the comparative analysis of the interactions between biomolecules(e-g.proteins,peptides and amino acids) and metal ions,the high specificity and stability of the binding of peptide molecules to metal ions have been determined.In combination with such advantages of peptide molecules as stability,flexibility,and easy modification,a series of analytical studies were conducted on their behaviors with metal ions.This paper was devoted to the construction of a fluorescent Cu(Ⅱ) biosensor based on the specific performance between peptides and Cu(Ⅱ) ions.In view of the flexible design and coordination sites of peptides,the interaction between peptides and Cu(Ⅱ) was deeply researched.A peptide(DDAEGHARHCR) specifically coordinated with Cu2+ was engineered by utilizing the known amyloid protein.And their binding ability and specifity were confirmed by the characterization of MALDI-TOF MS.With the formation of the ternary-competition system “peptides-Cu(Ⅱ)-calcein”,a unique fluorescence biosensor was constructed,thereby achieving the highly sensitive detection of Cu(Ⅱ) in water samples.As is known,Cu(Ⅱ) ions could effectively quench the fluorescence signal of calcein.When the functional peptide was introduced into the calcein-Cu(Ⅱ) system,the peptide with higher binding ability could promptly seize the Cu(Ⅱ) ions,greatly recovering the fluorescence signal of this system.Thus,the effective Cu(Ⅱ) sensing detection could be built.After optimizing the reaction temperature,reaction time,pH and calcein concentration,the detection of Cu(Ⅱ) in environmental water samples was also realized.Results demonstrated that the detection limit of this method for Cu(Ⅱ) was as low as 127 nmol/L,with a linear range of 0.12-13 μmol/L.To ensure the reliabity,the Cu(Ⅱ) concentrations was quantified by atomic absorption spectroscopy(AAS).The high consistency between AAS and our results indicated the accuracy and dependability of the work.Compared with other approaches for Cu2+ detection,the established method exhibited superiorities in simplicity,selectivity,efficiency and stability.Furthermore,the protocol involving the peptides design had a great application potential and a broad development prospect in pratical detection,which also offered a novel idea for the constitution of recognition elements.关键词：peptides;copper ions;metalloprotein;fluorescence detection
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发布时间：2023-04-18 - 摘要：The typical polycyclic aromatic hydrocarbons(PAHs) metabolite 1-napthol(1-OHNap) is ubiquitously existing in smokers blood.Its worth paying attention to the binding interaction between the most abundant transport albumin and 1-OHNap at molecular level.The crystal structures of human serum albumin(HSA) and bovine serum albumin(BSA) are different.There are still many studies using BSA as model protein to investigate the ligand-protein interactions.The main aim here was to explore the differences of binding mechanism between carrier protein HSA and BSA with 1-OHNap under the simulated physiological condition.The binding interactions between 1-OHNap and two serum albumin were investigated by steady-state fluorescence spectra,synchronous fluorescence spectra,CD spectra,fluorescence resonance energy transfer technique and molecular docking method.The fluorescence quenching experimental results showed that 1-OHNap interacted with both tryptophan(Trp) and tyrosine(Tyr) residues in HSA and BSA.The position and strength of characteristic fluorescence spectra of both HSA and BSA had been changed differently after binding with 1-OHNap.Meanwhile,the synchronous fluorescence spectra experimental results suggested that the binding interactions with 1-OHNap changed the polarity of the microenvironment of binding sites around the fluorophore in HSA.Besides,the binding interaction with 1-OHNap increased the polarity of the microenvironment around Trp residues in BSA.Then,the CD spectra were used to obtain the changes in the secondary structure of HSA and BSA after binding with 1-OHNap.The CD spectra experimental results indicated that the binding interaction with 1-OHNap caused the slight unfolding of polypeptide chains in both HSA and BSA.The amplitudes of the α-helical ratios of both HSA and BSA decreased after binding with 1-OHNap.Furthermore,the decreasing amplitude of the α-helical ratio of BSA was lower than that of HSA.The binding constants of 1-OHNap with HSA and BSA were calculated by using double logarithmic equation fitting.The binding constants of 1-OHNap with HSA and BSA were 1.49×104 L/mol and 8.76×103 L/mol,respectively.The molecular docking method was used to obtain the optimal binding sites of 1-OHNap in HSA and BSA,which were located at subdomain ⅡA and ⅠB,respectively.Then the distances between 1-OHNap at the optimal binding site and Trp214 in HSA,Trp 134 and Trp213 in BSA were obtained by Pymol software.The energy transfer efficiencies and apparent distances between the receptor 1-OHNap and the donar Trp residues in HSA and BSA were calculated by using the fluorescence resonance energy transfer technique.The apparent distances from 1-OHNap to Trp residues in HSA and BSA were calculated to be 1.53 nm and 1.42 nm,respectively.The above experimental results confirmed that the conformational changes of HSA and BSA after binding with 1-OHNap were significantly different.关键词：1-naphthol;fluorescence quenching;conformational change;human serum albumin;bovine serum albumin
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发布时间：2023-04-18 - 摘要：A rapid and low sequence-dependent miRNA detection method was established based on a “Y” DNA structure and a signal amplification function of isothermal exponential amplification reaction(EXPAR),which was named as Y-EXPAR.This method is easy to operate,with no need for DNA template labeling and a temperature change process.Meanwhile,the miRNA analysis was combined with fluorescence analysis technology,with Let-7b as a model target for miRNA detection because of its important role in cellular processes and human disease.According to the sequence of the model miRNA,two partially complementary DNA templates were designed to form a “Y” shaped structure together with the target miRNA,which could mediate a bidirectional amplification resulting in high efficiency and a short reaction time of 10 min.Furthermore,the results generated a good anti-interference for homologous sequences,distinguishing the let-7b from the let-7 homologous sequences with differences of 1-4 bases.Next,when used to detect other miRNAs with a lot of sequence changes(GC content),this “Y” template could also keep a good amplification performance,achieving the reduce of the dependence of amplification performance on template sequence.To achieve the best amplification efficiency,the reaction temperature,the dosage of endonuclease and polymerase were optimized.Under the optimal experimental conditions that the reaction temperature was 45 ℃,the concentration of Nt.BstNBI endonuclase was 0.04 U/μL,and the concentration of Vent(exo-) DNA polymerase was 0.06 U/μL,this method obtained a limit of detection down to 0.3 amol/L(corresponding to 1.8 copies of let-7b per 10 μL).And the linearity was maintained well within the range of 10 concentration orders.Results of the application in let-7b detection of tumor cell lysate showed a distinct difference between the POI values of 1-1 000 cells and the blank sample.And there was a linear relationship between the POI value and the logarithmic value of the number of cells.These results indicate that Y-EXPAR has an advantage in the detection of miRNA in actual samples.Benefited from the high efficiency,specificity,anti-interference and low sequence dependence of the amplification,this method provides a new idea for the rapid nucleic acid constant temperature amplification,and has a good application prospect in the research and clinical diagnosis of miRNA-related diseases.关键词：miRNA;isothermal exponential amplification reaction(EXPAR);sequence dependent;disease diagnosis
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发布时间：2023-04-18 - 摘要：Based on microchip electrophoresis-chemiluminescence detection(MCE-CL) platform,a new method of MCE separation assisted double cycle chemiluminescence signal amplification was established for the detection of HIV gene(HIV-DNA),with horseradish peroxidase-labeled DNA(HRP-DNA) as signal probe,utilizing HRP to catalyze the CL reaction of luminol and hydrogen peroxide and the hybridization of target molecules with DNA,and combined with T7Exo enzyme-assisted signal amplification.In this method,two DNA single strands P1 and P2 firstly formed P1/P2 double-stranded complexes.They then formed a ternary complex when the target HIV-DNA existed,which could be degraded specifically by T7Exo to release the HIV-DNA and P2 single strands.The released HIV-DNA was rehybridized with the P1/P2 double-stranded complex,and the T7Exo continued to degrade the complex.While the released P2 single strand was hybridized with HRP-DNA portion to form P2/HRP-DNA double strand,which was degraded by T7Exo,simultaneously releasing HRP-DNA fragment and P2 single strand.The released P2 sequence was rehybridized with HRP-DNA,which was degraded by T7Exo to produce a large number of HRP-DNA fragments.High sensitive detection of target molecules could be realized by double cycle signal amplification.Under optimized experimental conditions,the logarithmic values of HIV-DNA concentration in the range of 1.0×10-14-5.0×10-9 mol/L showed a good linear relationship with the chemiluminescence intensity of the system.The detection limit(S/N=3) was 1.6×10-15 mol/L.At four spiked levels of 0.10,0.25,1.0,10(×10-12 mol/L),the recoveries range from 93.0%-103%,and relative standard deviations(RSDs) was 0.50%-3.7%.The proposed method was applied to the analysis of HIV-DNA in human serum with satisfactory results.关键词：microchip electrophoresis;chemiluminescence;signal amplification;HIV-DNA
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发布时间：2023-04-18 - 摘要：A high performance liquid chromatography(HPLC) with fluorescence detection based on a simple pretreatment method was established for the simultaneous determination of 15 kinds of fluorescent whitening agents in food contact paper products,with widely used and low-cost ionic fluorescent whitening agents as well as some fluorescent whitening agents such as fluorescent whitening agent 393 and fluorescent whitening agent 184 concerned in the European Union and China as the research objects.The analysis objects included ionic and non-ionic fluorescent whitening agents,some of which were isomers,including ionic fluorescent whitening agents 220 and 24,and non-ionic fluorescent whitening agents 199A and 199B.At present,the chromatographic analysis methods for fluorescent whitening agents are mainly corresponding to ionic and non-ionic fluorescent whitening agents,and the chromatographic separations are mainly carried out with C18 column.However,there are few studies on simultaneous determination of the two types of fluorescent whitening agents and some of their isomers.In that case,a series of parameters such as chromatographic column,mobile phase,flow rate,pH value and elution gradient were optimized in this paper to achieve the chromatographic separation and simultaneous detection of 15 fluorescent whitening agents.Consequently,the samples were separated using an Agilent Pursuit 5 PFP(4.6 mm×250 mm×5.0 μm) by gradient elution,with acetonitrile,methanol and the solution of tetrabutyl ammonium bromide as the mobile phases.In the pretreatment process,the extraction solvent,extraction time,extraction volume and separation method were optimized to realize the effective extraction of fluorescent whitening agents from food contact paper products.Specifically,during the analysis process,the samples were crushed,and the one-step solvent extraction was applied to extract the fluorescent whitening agents in samples with alkaline extract solution through ultrasonic process.Subsequently,the extract solution was filtrated,and analyzed by high performance liquid chromatography.Results showed that there were good linear relationships for the calibration curves of 15 fluorescent whitening agents,with their correlation coefficients(r) not less than 0.998 9.The limits of detection and the limits of quantitation were in the ranges of 0.030-0.60 mg/kg and 0.10-2.0 mg/kg,respectively.Under the detection limited concentrations set in this paper,15 kinds of fluorescent whitening agents were found to exhibit no obvious fluorescence phenomenon by ultraviolet light illumination method,which indicated that the method reached a high sensitivity.The recoveries for 15 fluorescent whitening agents at three spiked levels ranged from 90.0% to 108%,with relative standard deviations of 0.70%-7.1%.The established method was successfully used for the determination of 13 commercial paper products with good practicability,simplicity and sensitivity.The establishment of this method could realize the further identification of the types and contents of fluorescent whitening agents in food contact paper with positive fluorescence phenomenon,which has a certain guiding significance for the quality and safety management and control of food contact paper products.关键词：fluorescent whitening agents;food contact paper products;high performance liquid chromatography;fluorescence detection
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发布时间：2023-04-18 - 摘要：A high-performance liquid chromatography-quadrupole time-of-flight mass spectrometric(HPLC-Q-TOF MS) method was established for the identification on constituents in Armeniacae Amarum Semen and Persicae Semen.Meanwhile,the chemical constitutions difference between Armeniacae Amarum Semen and Persicae Semen were analyzed by chemical pattern recognition methods-The sample was firstly extracted with methanol,then separated on an Agilent SB-C18 column(150 mm×3.0 mm,2.7 μm) by gradient elution,with 0.1% formic acid water-acetonitrile as the mobile phase,and finally analyzed by MS in positive and negative modes-The qualitative analysis of chemical compositions was proceeded by online database,Agilent TCM PCDL database and fragmentation regularities of mass spectra,which were compared with those of standard samples.A total of 29 constituents were identified,including 8 glycoside compounds,6 amine acids,9 organic acids and 6 other compounds,in which glycoside compounds such as amygdaloside,prunasin,mandelic acid amide-β-gentiobioside,benzyl-β-gentiobioside,etc.were the main non-volatility constituents in Armeniacae Amarum Semen and Persicae Semen-Propyl-β-gentiobioside was firstly reported in these two traditional Chinese medicines.The mass data were pretreated with Profinder software.Combined with SIMCA-P software,a statistical model for the discrimination of constituents difference between these two medicines was established by unsupervised principal component analysis(PCA) and supervised orthogonal partial-least squares discriminant analysis(OPLS-DA) multivariate pattern recognition techniques-A clear distinction between Armeniacae Amarum Semen and Persicae Semen was presented when PCA and OPLS-DA were used.15 compounds showed significant differences between these two medicinal materials,which were mainly composed of glycosides,amine acids and fatty acids.Importantly,the content of propyl-β-gentiobioside in Armeniacae Amarum Semen outclassed that in Persicae Semen,which may be used as the potential chemical marker to distinguish Armeniacae Amarum Semen and Persicae Semen.This research provided a good support for pharmacology research and quality control on Armeniacae Amarum Semen and Persicae Semen.关键词：Armeniacae Amarum Semen;Persicae Semen;high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry;chemical marker;quality control
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发布时间：2023-04-18 - 摘要：With the development of multiple-collector inductively coupled plasma mass spectrometry(MC-ICP-MS),non-traditional stable isotope system has received increasing interest.Meanwhile,cadmium(Cd) isotope is becoming a research hotspot in recent years due to its unique physicochemical properties and isotopic fractionation characteristics.In addition,Cd isotope has been widely used in the fields of marine chemistry,biochemistry and cosmic chemistry.Sample digestion is a vital step in the process of isotope analysis,and the quality of digestion method directly determines the accuracy of Cd isotope data.In the previous studies,the Cd isotope data obtained by different digestion methods had been investigated for some geological and environmental samples,but few reports had been focusing on the Cd isotope composition of biological samples,e-g.rice flour reference materials.Therefore,the advantages and disadvantages of different digestion methods as well as the effects of sample digestion methods on the Cd isotopic composition of plant samples(rice，reference materials and real rice samples) were further compared.Firstly,dry ashing,acid extraction,microwave digestion and high temperature digestion bombs method were used to digest seven stream sediment(GSD) reference materials,and the effects of sample digestion methods on the high precision Cd isotope detection were evaluated.After that,both microwave acid digestion and high temperature digestion bombs method were used to digest the two rice(GBW) reference materials and six real rice samples.Results showed that the Cd isotope results of stream sediment reference materials obtained by the high temperature digestion bombs were in good agreement with the reported values.However,in the case of dry ashing or acid extraction method,the recoveries for Cd in the stream sediment reference materials were a little too low(it could be as low as 72.8%) due to element loss or incomplete digestion,and the Cd isotope test results would significantly deviate from the true value(maximum deviation of the isotope value Δ114/110Cd reached to 0.24‰).It is worth noting that microwave digestion could achieve a recovery for Cd within 96.6%-98.8%,and the isotope results are in line with the values obtained by high temperature digestion bombs method within the analytical uncertainty(Δ114/110Cd ≤±0.04‰),which indicated that the microwave digestion method could be used to obtain accurate and reliable Cd isotope data.In the follow-up digestion of two rice reference materials and six real rice samples,the Cd isotope compositions obtained were the same as those of the above stream sediment reference materials(Δ114/110Cd≤±0.04‰),further verifying the reliability of microwave acid digestion.All the results demonstrated that microwave digestion was a reliable digestion method for Cd isotope analysis on samples of different matrix types.关键词：Cd isotope;digestion method;isotopic composition;sediment;rice
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发布时间：2023-04-18 - 摘要：Arsenic is widely present as various inorganic and organic species in nature,and exists mainly in the forms of As(Ⅲ) and As(Ⅴ) in environmental water.The environmental,biochemical and toxicological effects of arsenic depend on its existing form to a great extent.Therefore,the speciation analysis of arsenic in environmental samples is of great significance to environmental pollution monitoring and health risk assessment.Presently,inductively coupled plasma mass spectrometry(ICP-MS) has been widely used in the determination of trace arsenic.However,,some difficulties would be encountered inevitably when ICP-MS is directly applied to the speciation analysis of arsenic in real samples.For example,different arsenic species cannot be distinguished,insufficient sensitivity and polyatomic ion interference of 40Ar35Cl on 75As during ICP-MS detection cannot meet the requirements for real sample analysis.Therefore,sample pre-treatment is often used prior to the ICP-MS detection,to enrich target analyte,separate multiple arsenic species and/or remove complex sample matrix.The purpose of this work is to synthesize new types of magnetic sorbents for the enrichment of arsenic species,and to establish a new ICP-MS with magnetic solid phase extraction(MSPE) for the quantification of inorganic arsenic species in environmental samples.Herein,sulfhydryl(—SH) modified epoxy-modified magnetic nanoparticles(Fe3O4@SiO2@GMA—S—SH MNPs) were prepared,and a method of MSPE/ICP-MS was developed for the analysis of inorganic arsenic species(As(Ⅲ) and As(Ⅴ)) in water samples.It was found that As(Ⅲ) was selectively adsorbed on Fe3O4@SiO2@GMA—S—SH MNPs in the pH value range of 5.0-9.0,while As(Ⅴ) was hardly adsorbed under this pH condition.For the determination of As(Ⅴ),As(Ⅴ) was reduced to As(Ⅲ) by Na2S2O3/KI prior to MSPE-ICP-MS detection,and the content of As(Ⅴ) was obtained by subtraction.The factors affecting MSPE were investigated in details.Under the optimal conditions,the limit of detection(LOD) of the developed method was 1.5 ng·L-1,the enrichment factor was 150 fold,the linear range was 5-3 000 ng·L-1,and the relative standard deviation(RSD)(c=10 ng·L-1,n=7) was 9.6%.To validate the accuracy,the developed method was applied to the analysis of arsenic speciation in a certified reference material of GSB07-3171-2014,and the determined results were in good agreement with the certified values.This method was also applied to the analysis of As(Ⅲ) and As(Ⅴ) in tap water and environmental water.The concentrations of As(Ⅲ) and As(Ⅴ) in tap water were 0.036 μg·L-1 and 0.043 μg·L-1,while those in lake water were 0.24 μg·L-1 and 0.43 μg·L-1,respectively.Spiked experiment was also conduced,and the recoveries were in the range of 80.9%-101%,and the RSD range of 1.5%-10%.The developed method has the merits of low detection limit,high enrichment factor,fast adsorption/desorption dynamics and good tolerance to interferences,and is suitable for the speciation analysis of inorganic arsenic species in real samples.关键词：magnetic solid phase extraction;inductively coupled plasma mass spectrometry;arsenic speciation
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发布时间：2023-04-18 - 摘要：Molybdenum is widely used in steel,petroleum,chemical,electroplating,nuclear and other industries.The molybdenum contained in the waste water and residue may come into water environment through various routes.High intake of molybdenum will exert hazardous effects on human health.Thus the molybdenum content in water should be monitored.Conventional analytical methods such as atomic absorption spectrometry(AAS) and inductively coupled plasma atomic emission spectrometry(ICP-AES) can only detect the total amount of molybdenum,rather than the level of toxic Mo(Ⅵ).Therefore,it is necessary to develop sensitive and accurate analytical techniques for determination of Mo(Ⅵ).Proper sample preparation procedures for Mo(Ⅵ) are necessary prior to its instrument analysis due to its low concentration in water and the complexity in matrix composition.Meanwhile,polyethyleneimine(PEI) has lots of amino groups,part of which will be protonated under acidic condition.Hence,PEI could interact with Mo(Ⅵ) through coordination and electrostatic actions.In this work,polyethyleneimine modified magnetic nanomaterials(PEI-SiO2-Fe3O4) were prepared by heating and stirring,with polyethyleneimine and silicon-coated ferrosoferric oxide as the reactants.The PEI-SiO2-Fe3O4 was characterized by infrared spectroscopy(FTIR),field emission scanning electronic microscopy(FE-SEM) and vibrating sample magnetometry(VSM).Then the PEI-SiO2-Fe3O4 nanomaterial was used as the adsorbent for magnetic solid phase extraction of Mo(Ⅵ).The optimum SPE conditions were as follows:a solution pH value of 5.0,an adsorption time of 20 min and a sample volume no more than 300 mL.The adsorbed Mo(Ⅵ) was completely eluted with 2 mL of 20 g/L Na3PO4 for 2 min.Coupled with flame atomic absorption spectrometry,a new analytical method for trace Mo(Ⅵ) in water was developed.Under the optimized conditions,the calibration curve was linear over the concentration range of 10-200 μg·L-1 with a determinative coefficient(r2) of 0.999 8.The limit of detection for Mo(Ⅵ) was 1.3 μg·L-1.The precision of the method was examined by performing six replicate experiments with the same Mo(Ⅵ) concentration(50 μg·L-1),which yielded an intra-day RSD of 2.7% and an inter-day RSD of 3.4%.The average recovery for Mo(Ⅵ) was found to be 98.9%.The enrichment factor(EF) evaluated by the ratio of the slopes of the calibration curves with and without the MSPE procedure was 172.In addition,the common coexisting anions(Cl-,NO-3,SO2-4,Cr2O2-7 and PO3-4) and cations(K+,Na+,Ca2+ and Mg2+) did not interfered with the determination.The proposed method was applied to the detection of Mo(Ⅵ) in environmental water,drinking water and industrial effluent samples.The spiked recoveries ranged from 91.0% to 110% with the RSDs of 0.90%-6.1%.The developed method is rapid,sensitive and accurate,and thus is suitable for determination of trace amounts of Mo(Ⅵ) in various water samples.关键词：Mo(Ⅵ);polyethyleneimine;magnetic solid phase extraction;flame atomic absorption spectrometry
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发布时间：2023-04-18 - 摘要：Carcinoembryonic antigen(CEA) is a kind of glycoprotein that has been extensively investigated as a tumor marker for clinical diagnosis,which is routinely used as part of an individuals annual medical checkup in China.It is present in about 95% of all colon tumors and 50% of breast tumors and is also associated with ovarian carcinoma,lung cancer and other cancers.CEA is a preferred tumor marker to help predict outlook in patients with colorectal cancer.Breast cancer is the most widespread life-threatening cancer among women worldwide.It is a complex and heterogeneous disease composed of several subtypes with different morphological and clinical implications.One of the most important biomarkers for breast cancer is the carbohydrate antigen 15-3(CA15-3).The concentration of CA15-3 in blood serum could provide information from monitoring of therapy,which could also predict breast cancer recurrence after curative surgery.Hence,it is important to develop a highly sensitive analytical method for accurate and selective detection of CEA and CA15-3.Compared to one element tagging,the immunoassay of multi-elements can improve assay efficiency and reduce sample consumption.In this study,several immunoassay procedure parameters were examined,including effects of dwell time,concentrations of CeO2-SiO2NPs and UCNPs on the number of detection events.A new method for simultaneous determination of CEA and CA15-3 was developed using single particle inductively coupled plasma mass spectrometry(ICP-MS) coupled with magnetic immunoassay.Meanwhile,amino-modified magnetic nanoparticles were synthesized and conjugated with primary CEA antibody and primary CA15-3 antibody to extract the target biomarkers.The suspension solutions were separated with a permanent magnet.Single particles were directly introduced into ICP-MS with a custom,gas pressure-assisted sample introduction system.Carboxyl-functionalized up-conversion nanoparticles(UCNPs) and amino-functionalized cerium dioxide-silicon dioxide nanoparticles(CeO2-SiO2NPs) were employed to tag antibodies.The frequencies of transient signals of 174Yb and 140Ce were directly related to the concentrations of UCNPs and CeO2-SiO2NPs.CEA and CA15-3 could be quantified via the frequency of transient signal produced by single particle ICP-MS.Under the optimal conditions,the linear concentration ranges for CEA and CA15-3 were 0.02-100 ng·mL-1 and 0.05-50 U·mL-1,respectively.Their correlation coefficients were 0.994 0 and 0.987 0,respectively.The detection limits(LOD,S/N=3) of CEA and CA15-3 were 0.006 7 ng·mL-1 and 0.016 7 U·mL-1,respectively.The method was applied to the simultaneous detection of CEA and CA15-3 in human breast cancer serum with recoveries of 95.2%-98.9% and 95.5%-97.2%,and relative standard deviations(RSD) of 3.0%-4.6% and 3.4%-4.3%,respectively.关键词：inductively coupled plasma mass spectrometry(ICP-MS);nanoparticle;carcinoembryonic antigen（CEA）;carbohydrate antigen 15-3（CA15-3）;serum
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发布时间：2023-04-18 - 摘要：Metal organic frameworks(MOFs) are characterized with high specific surface areas which are beneficial to adsorption,while Au nanoparticles(Au NPs) are known to have excellent catalytic activity.Therefore,the composites of Au NPs and MOFs have a wide application in electrochemical sensing.In this work,the composites of Au NPs@NU-901 were prepared and characterized by transmission electron microscopy,X-ray diffraction,infrared spectroscopy and X-ray photoelectron spectroscopy.The results obtained testified the successful synthesis of Au NPs@NU-901.The electrochemical performance of Au NPs@NU-901/GCE toward the electrocatalytic oxidation of butylated hydroxyanisole(BHA) was investigated by linear sweep voltammetry(LSV) and differential pulse voltammetry(DPV).The experimental results showed that Au NPs@NU-901/GCE could catalyze the electrochemical oxidation-reduction reaction of BHA,and the signal was enhanced more greatly compared with those of bare/GCE,NU-901/GCE and Au NPs/GCE.In addition,the oxidation mechanism of BHA was investigated by LSV.By exploring the relationship between peak potential and pH values ranging from 2.2 to 8.0,as well as the relationship among peak potential and peak currents and scanning rates ranging from 50 mV/s to 250 mV/s,it was proved that the oxidation-reduction reaction of BHA on Au NPs@NU-901/GCE exhibited a process involving two electrons and two protons.In order to improve the detection sensitivity,the conditions,including supporting electrolyte,drop-coating volume,accumulation potential and accumulation time,were optimized.Under the optimal conditions,an electrochemical sensor based on Au NPs@NU-901 was fabricated for the determination of BHA with a linear range of 0.10-50 μmol/L(r2=0.994 8) and a detection limit (S/N=3) of 0.049 μmol/L.The reproducibility of this method was evaluated by nine parallel trials with nine different electrodes,with a relative standard deviation (RSD) of 3.6%,indicating that a good reproducibility was obtained.The anti-interference performance of the sensor was also studied.Results showed that 5 000-fold K+,Na+,Cl-,citric acid and glucose,2 500-fold SO2-4,2 000-fold sucrose,8-fold tert-butylhydroquinone and 2-fold butylated hydroxytoluene produced no interference on the determination of BHA.To investigate the practical application value,the sensor was used to detect BHA in three kinds of biscuit samples.It was noteworthy that the results of samples obtained by this method were highly consistent with those obtained by high performance liquid chromatography,indicating a good accuracy.Furthermore,the recovery experiments for real samples at three concentration levels were carried out,and the recoveries were within the range of 95.6%-104%.The sensor was successfully applied to detect BHA in biscuit samples.Overall,the electrochemical sensor based on Au NPs@NU-901 composites,with good selectivity,sensitivity and accuracy for electrochemical oxidation of BHA,was successfully used in the quantitative determination of BHA in biscuit samples.This study provided a good demonstration for the application of noble metal nanoparticles and MOF composites in electrochemical field.关键词：metal organic frameworks;Au nanoparticles(Au NPs);electrochemical sensor;butylated hydroxyanisole;biscuit
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发布时间：2023-04-18
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