最新刊期
卷 37 ， 期 10 ， 2018
- 摘要：To date，more than 150 modifications have been found in various species of RNA molecules.The modifications do not change RNA sequence，but they play critical roles in a variety of cellular processes.Recent research advances demonstrate that RNA modifications are dynamic,and many of them could finetune gene expression.The elucidation of biological functions of RNA modifications relies on the accurate detection and mapping of these modifications.However，RNA modifications typically exist in low abundance in vivo,and analysis on RNA modifications is generally challenging.Over the past decade，great advances have been made in the development of analytical methods of RNA modifications，which largely promote the functional studies of RNA modifications.In this review，the merits and weaknesses of the established methods for study of RNA modifications are summarized，and the development of analytical methods and techniques of RNA modification is prospected.关键词：RNA modification;analytical method;mass spectrometry analysis;sequencing analysis
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发布时间： - 摘要：Fluorescent metal nanoclusters（MNCs）,as novel fluorescent materials,exhibit good biocompatibility and excellent physicochemical properties,which have attracted more and more attention in various fields,especially in the biomedical field.In this review,the synthesis methods and optical properties of various metal nanoclusters are described.Then,the applications of metal nanoclusters in the biomedical field are reviewed from three aspects of biosensing,bioimaging and cancer therapy.Finally,the future challenges and application prospects of the MNCs in biomedical application are discussed.关键词：metal nanoclusters;biomedical application;biosensing;bioimaging;cancer therapy
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发布时间： - 摘要：Ion mobility spectrometry（IMS）is a technique characterizing compounds based on the mobility of gas phase ions under the joint influence of electric field and gas flow.Ion mobility spectrometry-mass spectrometry（IMS-MS）combines the advantages of ion mobility separation and mass spectrometry analysis.In addition to differentiation by the mass-to-charge ratio（m/z）,the ions can be separated according to their sizes and shapes,thus providing a new dimensional information of mobility based separation and measurement.When coupled with chromatographic technique,IMS-MS can be used to obtain four dimensional data,including retention time,drift time,m/z and signal intensity to improve the analysis accuracy and specificity.The collisional cross section（CCS）of ions can also be calculated to explore the structural information.In this paper,recent advances of IMS-MS in the fields of public security,drug testing,food safety,environmental monitoring,pharmaceuticals analysis and biomacromolecules were reviewed.The trends and prospects for the development of IMS-MS were discussed,which may provide a theoretical support and a technical guidance for the researchers engaged in relevant fields.关键词：ion mobility spectrometry（IMS）;ion mobility spectrometry-mass spectrometry（IMS-MS）;review
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发布时间： - 摘要：Organic nanomaterials（ONMs）generally refer to nanomaterials based on lipids,proteins,polysaccharides and polymers.In recent years,ONMs have been widely used in food,agriculture,and biomedical industries with the rapid development of nanotechnology.Although the unique properties of ONMs endow them great application potentials,they still have some potential toxicity to organisms.Some ONMs are difficult to degrade,and they might be discharged into the environment through human activities,and accumulated in the organisms.Therefore,the safety assessment on ONMs has attracted increasing research interest.This also raises new challenges toward their characterization and analytical methods.The analysis of ONMs often includes procedures of sample preparation,separation,characterization and detection.Many techniques are involved such as filtration,centrifugation,chromatography,electron microscopy,spectroscopy and mass spectrometry.The current progresses in the application and development of analytical methods of ONMs are summeried in this article.The perspectives on the future research in this area are also proposed.关键词：organic nanomaterial(ONMs);analytical method;chromatography;mass spectrometry;microplastic
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发布时间： - 摘要：Photodynamic therapy（PDT）has emerged as one of the important therapeutic options for cancers.However,traditional photosensitizers have some defects such as poor selectivity and low photo-stability,which limit their clinical applications.Fortunately,some fluorescence molecules with aggregation-induced emission（AIEgens）characteristics could be used as a novel photosensitizer.The utilization of AIEgens has recently been developed at a tremendous pace,as compared with other materials,AIEgens possess various distinct advantages such as good biocompatibility,excellent fluorescent properties,simple preparation and modification,perfect size of nanoparticles for enhanced permeability and retention effect,etc.The advantages of AIEgens in PDT are introduced in this review,and the originative studies in PDT based on AIEgens in recent five years are systematically summarized.AIEgens would be a promising multifunctional material in PDT,and facilitate significant advancements in field of cancer therapy.关键词：photodynamic therapy;photosensitizer;aggregation induced emission
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发布时间： - 摘要：With the rapid developments of subjects including drug discovery,proteomics,traditional Chinese medicine,etc.,the demands for high sensitive and throughput analytical methods become urgent.Chromatographic analysis technology confronts a lot of new challenges.Traditional packing columns still remain a series of inadequacies,such as high cost,low stability,difficult preparation process,high backpressure etc.Recently,polymeric monolithic columns have been proved to be an effective alternative for packed columns,and have attracted considerable interest owing to their facile preparation and good column characteristics,such as permeability and efficiency.To satisfy the requirements for separation and analysis of increasingly complex compounds,the developments for new polymeric monolithic columns with various functionalities have been paid great importance.In this review,the classifications,functionalities,and applications of monolithic colomns are comprehensively introduced,especially the polymeric monolithic column.关键词：monolithic column;organic polymer;capillary liquid chromatography;pharmaceutical analysis
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发布时间： - 摘要：Digital microfluidics（DMF）is an emerging liquid handling technique based on arrays of microelectrodes for precise control of discrete droplets.This platform based on electrowetting on dielectric（EWOD）has the characteristics of automation,addressability,flexible device configuration,and easy combination with other techniques compared with the conventional microchannel based fluidics.The mechanism for droplet actuation,the structure and fabrication of microfluidic chips and their applications in the field of bio analytical chemistry are presented in this paper.And an outlook for the future applications of DMF is also proposed.关键词：digital microfluidics;electrowetting on dielectric;lab on a chip;bioanalysis
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发布时间： - 摘要：Surface enhanced Raman spectroscopy（SERS）is a novel and rapid detection technique，and it has a great practical value in food safety field with many advantages such as rich information，high sensitivity，easy operation and non destructive testing.The development，principle，classification and application of substrate,and detection modes of SERS are introduced in this article，while the latest progresses of the rapid detection by SERS in food harmful small molecular substances，foodborne pathogens and heavy metal pollution as well as mycotoxins are also summarized.Furthermore，some problems to be solved and the developing trend of SERS in food safety detection are both proposed.关键词：surface enhanced Raman spectroscopy（SERS）;food safety;rapid detection;review
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发布时间： - 摘要：Indium tin oxide(ITO) thin-film electrodes have good physical(high conductivity and good light transmission) and chemical properties.Proper surface modification could further extend their applications in electroanalytical chemistry.Based on the present research status，the preparation and cleaning processes of ITO electrodes are briefly introduced in this paper，and the different modification methods are summarized，in which three of the most frequently employed methods，ie.chemical adsorption，silanization and electrochemical grafting are emphatically introduced.Finally，the challenges and future application prospects in the surface modification of ITO thin film electrode are briefly discussed.关键词：ITO electrode;surface modification;chemical adsorption;silanization;electrochemical grafting
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发布时间： - 摘要：Hydrogen sulfide（H2S），a kind of colorless，rotten egg smell and corrosive gas，is one of widespread environmental pollutions.As a kind of highly toxic and volatile gas，H2S affects several different systems in human body even exposed at low concentrations.Therefore，the rapid，highly sensitive and real time detection of H2S plays an important role in fields of Industrial production，public safety，environmental monitoring and medical healthy.In this paper，the significant research progresses in H2S gas sensors based on electric charge and optical principle in recent five years have been reviewed，especially those focusing on the development of sensing materials and sensing technologies.Meanwhile，the problems and the future prospects for these two types of H2S gas sensors are discussed.关键词：hydrogen sulfide;electric charge type gas sensor;optical gas sensor;review
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发布时间： - 摘要：Microplasma is produced by confining the dimension of plasma to a limited space.As a new type of excitation source，microplasma has the advantages of low power consumption，small size and low cost，and shows a great application potential in the miniaturization of optical emission spectrometric instruments.In this paper，the new applications of optical emission spectrometric（OES）systems based on microplasma excitation sources in the field of analytical chemistry are introduced.At present，microplasma OES system is not only able to use in the direct determination of analytes in gas or liquid phase，but also possesses a series of coupling techniques with gas chromatography（GC），chemical vapor generation（CVG），electrothermal vaporization（ETV），microelectrodialysis（μED）and capillary electrophoresis（CE），greatly expanding the scope of its application.In the future，the performance of the microplasma OES system will be further improved by enhancing the excitation capability of the microplasma itself and choosing a suitable sampling approach.At the same time，the development for related instruments will provide a reliable tool for the field analysis on trace elements.关键词：microplasma;excitation source;optical emission spectrometry;miniaturization;trace analysis;review
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发布时间： - 摘要：Fluorescence blinking means that,even under the constant illumination,the fluorescence emission of a single fluorophore exhibits surprising intermittency,ie.the random,significant and frequent switching between “bright” and “dark” states.This phenomenon was first discovered in organic fluorescent molecules,fluorescent proteins and semiconductor quantum dots.Subsequent studies showed that it was often observed in versatile types of fluorescent nanomaterials.Fluorescence blinking has not only deepened greatly the fundamental understanding on the photophysical processes of molecules and semiconductors,but also brought opportunities and challenges for the in depth applications of fluorescent materials in broad fields such as biosensing,imaging and optoelectronic devices.In this review,the main characteristics and research status of fluorescence blinking are briefly described,and the photophysical mechanism behind it is also systematically introduced.By reviewing the fluorescence blinking characteristics of several kinds of typical nanomaterials,the advantages and disadvantages of fluorescence blinking are discussed.Finally,the future trend in this field is prospected.关键词：single particle analysis;fluorescence blinking;semiconductor quantum dots;fluorescence imaging;review
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发布时间： - 摘要：Protein glycosylation is one of the most important post translational modifications.However,the great challenges for glycosylation of protein/peptides are the inherently low abundance and the poor ionization efficiency in mass spectrometry identification.Therefore,the specific enrichment before MS identification is indispensable.The basic principles,characteristics and recent progresses of the enrichment approaches for glycosylated proteins/peptides are reviewed,and the development prospects of the enrichment approaches for N glycosylated proteins/peptides are also outlined.关键词：glycoproteomics;N glycosylation;glycopeptides;glycoproteins;enrichment
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发布时间： - 摘要：Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein（CRISPR/Cas）is an adaptive immune defense system based on RNA for most bacteria and archaea.CRISPR/Cas technology modified from CRISPR/Cas system has become a strong genome editing tool，which has been widely applied in gene function analysis，gene modification and therapy.Other than being a strong genome editing tool，the “collateral cleavage” of type Ⅱ Cas has been employed as a rapid，inexpensive，and sensitive nucleic acid detection tool，exhibiting a great promise in nucleic acid molecular diagnosis.The representative research progresses in nucleic acid detection based on the type Ⅱ Cas are reviewed in this article，and an outlook on the application of CRISPR/Cas system in molecular diagnosis is proposed.关键词：CRISPR;Cas proteins;specific recognition;collateral cleavage;nucleic acid detection
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发布时间： - 摘要：A sensitive and convenient method was established for the analysis of twelve kinds of pesticide in root,leaf,seed meat and seed shell of lotus,mud and field water by ultrahigh performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）.The solid samples were extracted with acetonitrile/water,then salted out with sodium chloride and following by a centrifugal separation,finally purified and eluted with a PestiCarb-SPE column.The water samples were simply enriched,cleaned up and eluted with a BondElut C18-SPE column.The eluted fractions were analyzed by UPLC-MS/MS,and quantified by the matrix external standard method.The mass fragmentation pathway and matrix effect of twelve pesticides were also investigated.The calibration curves for the target compounds were linear in the concentration range of 0005（0010）-2500 mg/L,with their correlation coefficients（r2） more than 097.The average recoveries（AR） for twelve pesticides at high,middle and low spiked levels in lotus leaf,root,seed and seed shell were between 756% and 116%,with relative standard deviations（RSDs） of 13%-251%,while the AR.for other eleven pesticides except prochloraz in mud were 646%-104% with RSDs of 09%-95%;Besides,the AR.for the analytes in field water ranged from 712% to 101% with RSDs of 09%-169%,except that the AR.for clothianidin at low level,prochloraz and indoxacarb at middle and low levels were less than 70%.The limits of quantitation（LOQs） of this method were not more than 001 mg/kg and 01 μg/L,except clothianidin.After 10% clomazone-metolachlor-prometryne granules were spread into the lotus root fields by dosages of 630 g ai/ha and 945 g ai/ha in one time,final residue test was investigated by this method.Results showed that there were no clomazone and metolachlor residues in lotus root,lotus seed and lotus leaf samples,and the residual amounts of prometryne were not more than 0022,0166,0012 and 0181 mg/kg in the lotus root,lotus seed shell,lotus seed meat and lotus leaf samples,respectively.关键词：multi pesticide residue analysis;ultrahigh performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）;lotus root;lotus seed
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发布时间： - 摘要：In this work，four types of water soluble carbon dots(CDs) with excellent optical properties were fabricated through hydrothermal(HT) or microwave(MW) assisted approach，using aconitic acid(AA) as the carbon precursor，and ethylenediamine(EDA) or urea as the co doping reagents.Fluorescence spectroscopy showed that among these CDs，three emitted blue fluorescence and one emitted yellow fluorescence.Subsequently，one blue fluorescent AA&EDA-HT-CDs with the highest absolute quantum yield of 57% and yellow fluorescent AA&Urea-MW-CDs with an absolute quantum yield of 44% were selected，and then a series of detailed characterizations were conducted for the systematical investigation on their size distribution，chemical composition and surface groups，etc.Furthermore，the responses of as prepared CDs toward metal ions as well as their cytotoxicity were evaluated.Finally，the prepared AA derived CDs were successfully applied in cellular bioimaging.关键词：aconitic acid;carbon dots;emission control;fluorescent sensor;cell imaging
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发布时间： - 摘要：A novel method combining ultrasound assisted extraction with single particle inductively coupled plasma-mass spectrometry（SP-ICP-MS）was developed for the analysis of nano TiO2 in sunscreen.To obtain the optimal extraction and analysis conditions,the experimental factors such as extraction solvents,dwell time and number concentration of nano TiO2 were investigated.Result showed that the optimum dwell time was 3 ms and the upper concentration limit for nano TiO2 was 4×107 particles/mL.The nano TiO2 in sunscreen could be extracted effectively by ultrasound assisted extraction with 01% Tritonx-100 and 5% ethanol as extracting agents.The method could be used for the detection on nano TiO2 in sunscreen with a detection limit for number concentration（LODconc）of 1×104 particles/mL and a detection limit for particle size（LODsize）of 35 nm.With the advantages of simplicity,rapidness,good sensitivity and accuracy,the method could be applied in the simultaneous determination and characterization on concentration and particle size distribution of nano TiO2 in sunscreen.关键词：single particle inductively coupled plasma-mass spectrometry（SP-ICP-MS）;ultrasound assisted extraction;nano TiO2;sunscreen
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发布时间： - 摘要：A reliable and sensitive method was developed for the determination of BPA migration in toys by high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）.The migration conditions based on European toy safety standard EN 71-10:2005 with water as simulant were modified.The sample was filtrated with syringe filters made of mixed cellulose esters（MCE）,then directly determined by HPLC-MS/MS.Furthermore,the influences of syringe filters were intensively investigated,and the MCE filters had satisfactory BPA recoveries larger than 90%,whereas other filters made of polyamide（PA,nylon 66）and polyether sulfone（PES）resulted in significant loss of BPA.There existed a good linearity of the method in the range of 2-100 μg·L-1 with correlation coefficients（r2）greater than 0999.The limits of detection（LOD）were in the range of 030-052 μg·L-1,and the limits of quantitation（LOQ）were 100-172 μg·L-1.The spiked recoveries were in the range of 965%-106% with RSDs（n=7）of 20%-86%.The established method was successfully applied in the determination of migration of trace BPA in toys,avoiding the BPA loss caused by improper selection of syringe filters,which could meet the requirements for newly adopted BPA migration limit（004 mg·L-1）specified in the EU Directive 2017/898.关键词：bisphenol A;migration;toys;high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）
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发布时间： - 摘要：A three dimensional（3D） porous conducting PEDOT nanocomposite doped with gold nanoparticles（AuNPs） was fabricated by polymerizing 3,4 ethylenedioxythiophene（EDOT）monomers and gold nanoparticles on a template of 3D arrayed polystyrene（PS）nanospheres,then removing the PS template.The nanostructure of prepared 3D porous AuNPs/PEDOT exhibited an excellent electrocatalytic property toward the oxidation of nitrite owing to its unique microstructure,where the doped AuNPs provided many active sites for the oxidation of nitrite,and the 3D porous structure facilitated the diffusion of nitrite molecules and accelerated the electron transfer.Based on this,the modified electrode was used in the detection of nitrite with a detection limit of 70 nmol/L and a wide linear range of 02-2 200 μmol/L.With the advantages of excellent selectivity,long term stability and good reproducibility,this sensor was applied in detection of nitrite in practical samples,and the results were consistent with those obtained by the standard method.
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发布时间： - 摘要：In this paper,the water soluble copper-silver nanoclusters（Cu-AgNCs）with red fluorescence were prepared by one step method with D penicillamine as ligand under mild conditions.The morphology,structure and fluorescence properties were characterized.Result showed that the quantum yield of the prepared nanoclusters reached up to 96%,and there was a good linear relationship between fluorescence intensity and temperature of the nanocluster in the range of 279-355 K.With the increase of temperature,the fluorescence intensity decreased.In addition,the results of MTT experiments showed that as the synthesized Cu-AgNCs exhibited a low toxicity and a good biocompatibility,they could permeate into E.coli cells,and enable measurements over the physiological temperature range of 293-313 K with the use of the confocal fluorescence imaging method.The results showed that the prepared Cu-AgNCs were expectable to use as a photoluminescence thermometer and biosensor in fluorescence imaging and other fields.关键词：copper silver nanoclusters;temperature response;E.coli;fluorescence imaging
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发布时间： - 摘要：High resolution mass spectrometry（HRMS)was used to study and characterize the background ions under direct analysis in real time（DART) ionization conditions,and the possible sources of these signals were traced and assigned.The research showed that the background ions are mainly generated under the positive ion mode,which may derive mainly from plasticizers and polydimethylsiloxane in the lab environment.The polydimethylsiloxane may come from the pump oil vapor.Understanding and mastering of these background ions will be favorable in the research and testing by DART-MS technique.Firstly,these background signals are stable and do not produce significant interference in sample analysis of DART.Therefore,the stability and accuracy for HRMS spectrometer could be investigated with no need of any internal standard compounds added deliberately.Secondly,understanding of these background ions will also help to avoid erroneous judgment in DART mass spectrometry analysis on complex systems.关键词：direct analysis in real time;high resolution mass spectrometry（MS);background ions
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发布时间： - 摘要：A method of infrared photodissociation（IRPD）spectroscopy was developed for the determination of phenylalanine substituted L serine octamer ions.The phenylalanine substituted L serine octamer ions were generated by electrospray ionization（ESI）and studied by mass spectrometry（MS）coupled with infrared photodissociation（IRPD）spectroscopy.Chiral preference was found existing in such cluster ions.IRPD experiments showed that the ions of ［L Ser7+L/D Phe1］H+ and ［L Ser6+L/D Phe2］H+ were observed in the range of 2 700-3 600 cm-1.Chiral differentiation was fulfilled by comparing their IRPD spectra or IRPD mass spectra obtained at some special wavenumbers.关键词：electrospray ionization（ESI）;infrared photodissociation（IRPD）spectroscopy;chiral differentiation;phenylalanine;serine octamer
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发布时间： - 摘要：A method of high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）was presented for the determination of five halogenated methyl sulfonic acids（HMSAs）in sludge from municipal sewage treatment plant.Through investigation on extract solvent，extraction method and times，the optimum conditions were obtained as follows:the mixture of methanol and water（1∶1，by volume）was selected as extraction solvent，samples were continually oscillated at 350 r/min for 1 hour，and extracted once.Under the optimized conditions，the extraction efficiencies were（484±28）%，（683±09）%，（810±48）%，（380±11）% and（991±12）% for chloromethanesulfonic acid，dichloromethanesulfonic acid，trichloromethanesulfonic acid，bromomethanesulfonic acid and trifluoromethanesulfonic acid，respectively.The calibration curves for the analytes were linear in the range of 005-50 μg·kg-1 with their correlation coefficients（r）larger than 0991.The limits of detection（LOD）of the method ranged from 0003 to 0018 μg·kg-1 for HMSAs，and the limits of quantitation（LOQ）were in the range of 0010-0059 μg·kg-1.The spiked recoveries for HMSAs in sewage sludge were in the range of 738%-101% with relative standard deviations of 23%-125%.关键词：halogenated methyl sulfonic acids;sewage sludge;high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS）
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