The Construction And Application Research Of Electrochemiluminescent Sensor Based On CdTe Nanocomposite

Electrochemiluminescence?ECL?has the advantages of both electrochemistry and chemiluminescence.It has the characteristics of simple operration,fast analysis speed,wide linear range and high sensitivity.With the development of nano-technology,the application of ECL sensing technology,such as nano-gold,quantum dots,carbon nanotubes,titanium dioxide and so on,has attracted more and more attention.So in this paper,CdTe quantum dots and CdTe@ZnSe nuclear shell quantum dots are synthesized by hydrophase synthesis method.The synthesized quantum dots are combined with nanomaterials to construct ECL sensors based on CdTe nanocomposites.Achieve the determination of trace drug content analysis.The main resear work is divided into the following parts:1.Synthesis and characterization of CdTe quantum dots.CdTe quantum dots were prepared water-phase synthesis method,and synthesis conditions of CdTe from pH,Te/Cd ratio,and heating reflux time to obtain CdTe quantum dots solutions of different particle sizes were studied.It was characterized by X-ray diffraction,scanning electromicroscopy,ultraviolet absorption spectroscopy,fluorescence spectroscopy and fluorescence lifetime method.With the extension of the synthesis time,the ultraviolet absorption peak and the fluorescence emission peak of CdTe gradually undergo a red shift.The fluorescence intensity is first enhanced and then reduced.The fluorescence lifetime increases gradually,and the CdTe quantum dots with good fluorescence propertieswere obtained,which can be used as a follow-up application.2.A molecularly imprinted electrochemiluminescence sensor based on CdTe and multiwall carbon nanotubes complexes for sensitive detection of Clenbuterol hydrochloride.A molecularly imprinted electrochemiluminescence sensor for the determination of Clenbuterol hydrochloride?CLB?was developed by using the combination of molecularly imprinted technique and ECL technique.Pyrrole was taken as monomer and CLB was taken as template molecule.The molecularly imprinted polymer?MIP?film containing specific CLB recgnition sites was prepared by electrochemical polymerization and used as selective recognition materials.CLB was determined by combination of CdTe and multiwall carbon nanotubes complexes?CdTe@MWCNTs?with MIP film.As the large specific surface area of MWCNTs,CdTe can be loaded on MWCNTs and CdTe can enhance ECL signal sensitivity.Accerding to the phenomenon of ECL signal quenching caused by the occupation of CLB recognition site,a new method for detecting CLB content was proposed.Under optimized conditions,the linear range of CLB was between 2.3×10^-9and 1.5×10^-5mol L^-1,and the detection limit was 1.0×10^-99 mol L^-1?S/N=3?.And CLB in pig samples has been successfully determined,which provides an effective method for CLB decection in practical application.3.Determination of Ribavirin by TiO₂-CdTe@ZnSe electrochemiluminescence sensor.The TiO₂-CdTe@ZnSe ECL sensor for the determination of Ribavirin?RBV?was constructed by synthesizing CdTe@ZnSe nuclear shell quantum dots in aqueous phase,and the ECL properties of the sensor were studied.The results show that the large specific surface area of TiO₂ can increase the carrying capacity of CdTe@ZnSe and enhance the transmission ability of electrons.CdTe@ZnSe has the signal amplification effect on the system,when a certain amount of RBV was added,the ECL signal was obviously quenched.So a new method for determination of RBV was established.Under optimized conditions,the logarithm of RBV concentration has a good linear relationship with the relative ECL intensity in the range of 2.0×10^-102.0×10^-66 mol L^-1.The detection limit?S/N=3?was 6.7×10^-11mol L^-1.The method was successfully applied in the detection of RBV in the injection.4.DeterminationofL-DOPAbyAuNPs/CdTe@ZnSe-MWCNTs electrochemiluminescence sensor.AuNPs was synthesized by the reduction of chloroauric acid with sodium citrate.The ECL sensor of AuNPs/CdTe@ZnSe-MWCNTs was constructed by AuNPs,CdTe@ZnSe,MWCNTs.AuNPs acts as substrate for the sensor,fromotes electronic transmission,the ECL signal strenngth of the system enhanced by CdTe@ZnSe and AuNPs.Followed by the addition of L-DOPA,the ECL signal of the system was gradually enhanced.So a new method for determination of L-DOPA content was established.Under optimized conditions,the linear range of L-DOPA was between 2.0×10^-1010 and 2.0×10^-55 mol·L^-1.The content of L-DOPA in injection was determined with satisfactory results.