Three Kinds Of Nano-material Modified Electrode And Its Application In Biochemistry

Nanomaterials have been studied extensively due to their large surface area, highsurface activity, and strong affinity. Also nanomaterials can enhance the capacity andstability of biological molecular adsorption. Current responses can be improved anddetection limit extended, when the nanomaterials modified electrodes are employed.Also they indicate the wide application prospect in electroeatalysis and sensormaterials. In this thesis, several kinds of nanometer material modified electrode wereprepared, and the fundamentals of electrochemistry research were illustrated. Thedetails are listed below:Chapter one: Based on extensive research of literature, the basic characteristics,classification and application of the nanomaterials were introduced, Preparation,characterization, and application of the modified electrode were introduced. Theauthors reviewed the recent progress about the nanomaterials modified electrodes andthen put forward the research goal of this dissertation.Chapter two: A novel type of CdTe Quantum dots/L-cysteine/gold nanoparticles/multi-walled carbon nanotube modified glassy carbon electrode （CdTe QDs/L-Cys/AuNP/MWCNTs/GCE） has been developed and used for the simultaneous determinationof dopamine and serotonin. The electrode was prepared using a layer by layer strategy,in which the preparations include following procedures: the fixation of MWCNTs,electrodeposition of gold nanoparticles, the assemble of L-Cys and binding of CdTeQDs. The performance and electrochemistry of the modified electrode wasinvestigated by voltammetry. Cyclic and differential pulse voltammetric resultsindicated that the modified electrode exhibit stable and sensitive current responses to5-HT and DA, and separate anodic peaks of5-HT from those of DA, which anodicpeaks of5-HT and DA are overlapped in common glassy carbon electrode. Theresponse of the electrode was linear with the dopamine concentration in the rangefrom2.0×108to5.0×106mol/L, and the serotonin concentration in the range from1.0×108to1.5×106mol/L. The novel electrode has been successfully applied for thesimultaneous determination of dopamine and serotonin in urine. Chapter three: A novel molecular imprinted film/Au nanoparticlar modifiedglassy carbon electrode, L-Cys/Au NP/GCE （MIP）, has been prepared byelectrochemical deposition of gold nanoparticles （Au NP） and electrochemicalassembled L-cysteine at the surface of GCE using bromophos ethyl as templatemolecular. The results indicated that L-Cys/Au NP/GCE （MIP） can selectivelyrecognize bromophos ethyl and be applied for the electrochemical determination ofbromophos ethyl in the spiked sample. Under the optimum conditions, theelectrochemical response is directly proportional to the bromophos ethylconcentration in the range from2.5×10^-6to17.5×10^-6mol/L, with a detection limit（S/N=3） of8.3×10^-7mol/L. Experiments also showed that the L-Cys/Au NP/GCE（MIP） has good stability and reproducibility.Chapter four: A novel type of Nafion/gold nanoparticles modified glassy carbonelectrode （Nafion/Au NP/GCE） has been developed and used for determination ofclenbuterol. In BR buffer （pH2.0）, CLB gave an obvious anodic peak at0.38V（vs.Ag/AgCl） by differential pulse voltammetry. The peak current is proportional to theconcentration of CLB over the rage of1.0×10^-7～2.0×10^-5mol/L. The detectionlimit is1.6×10^-8mol/L. The method was applied to the assay of CLB in serum withsatisfactory results.