Based On Mn-doped ZnS QDs Temperature Phosphorescence Detection Of Antibiotics And Ceftriaxone Sodium Sulfadiazine

Antibiotic drug is widely used for infectious diseases treatment in clinic because of its activity to inhibit or kill pathogenic microorganisms.However,toxic and side effect to human body caused by excessively use of antibiotic and environmental problem due to abuse of antibiotic also attract people's attention.Therefore,to achieve a simple and rapid detection of antibiotic is the basic premise of evaluating the efficacy as well as toxic and side effect of antibiotic.At present,the major methods to detect antibiotic are chromatography,fluorescence analysis,capillary electrophoresis and so on,which have some disadvantages,such as,expensive instrument,sophisticated operation and lower sensitivity.Thus,it is very significant to develop an effective and sensitive method to detect antibiotic.In recent years,as a new nano-luminescence material,quantum dots(QDs)show a broad application prospect in the field of medical detection,fluorescence labeling,optical sensing and optical encoding because of its excellent optical,electronic and surface paintability,and thus provide a new technical measure for sensitive detection of different analytes.However,fluorescent quantum dots are often interfered by background fluorescence in biological fluids.,but phosphorescent quantum dots can overcome this disadvantage.Accordingly,this paper develops two kinds of phosphorescence detection method for sulfadiazine sodiums(SDS)and ceftriaxone(CTRX)based on room-temperature phosphorescence(RTP)characteristics of Mn-doped ZnS quantum dots.The main contents are as follows:(1)Using 3-mercaptopropionic acid(MPA)as the stabilizer,ZnS:Mn quantum dots(QDs)were synthesized via water phase method.The morphologies of the QDs characterization by means of transmission electron microscopy(TEM),X-ray diffraction spectroscopy(XRD)and phosphorescence spectra.The nanoparticles were nearly completely spherical,uniform,and with good dispersion and with an average diameter of 3.5 nm(2)With the preparation of quantum dots,established a new method for the detection of sulfadiazine sodium(SDS),in pH 7.4 phosphate medium,through electrostatic interaction,SDS and quantum dots produced new non radiative centers,leading to the quenching of phosphorescence quantum dots,The quenching intensity had a good linear relationship with the concentration of SDS.Its linear range was 4-400 M,the correlation coefficient R=0.99,the detection limit was 0.78 M,the relative standard deviation was 2.6%.The method could avoid interference in biological fluids autofluorescence and scattering light,no need to add any deoxidizing agent and inducer.This method greatly improved the efficiency of detection of trace sulfadiazine sodium.(3)Using Bovine serum albumin as a surface modifier.By chemical coupling to the success of the BSA modified Mn-doped ZnS quantum dots surface.The Mn-doped ZnS QDs/BSA nanohybrid was prepared.BSA can effectively recover the defect on the surface of theMn-doped ZnS QDs,so the after the phosphorescence intensity of Mn-doped ZnS QDs can be enhanced after the conjugation between BSA and ZnS:Mn QDs.On this basis,we build a new sensor for ceftriaxone detection.This sensor is simple,sensitive,quick.And this sensor has a detection limit of 0.14?M and the linear range from 0 to 30?M.According to tthe analysis of the Construction mechanism for the phosphorescent sensing using UV absorption spectrometry,reso nance scattering spectroscopy and circular dichroism,we found that BSA can interact with quantum dots via covalent bond.However,BS A combines with CTRX by electrostatic interaction,which leads to t he change of charge distribution in BSA.Therefore,the hydrogen bo nds for maintain its helical structure changed,and further had an eff ect on the surface structure of the quantum dot-BSA.Thus a new n on-radiative center formed,which resulting in the room temperature phosphorescence intensity of Mn doped ZnS quantum/BSA nanoco mposite reduced significantly.This study established fluorescence detection method two antibiotics,to expand the room temperature phosphorescence quantum dots provide a little idea in the field of detection of antibiotics.