The Preparation And Application Of Three Kinds Of Chemical Modified Electrode Based On Graphene

Graphene is a single two-dimensional(2D) layer of carbon nanometer material. Itis Being more and more concerned because of strong conductive capacity, Largespecific surface area, prefect affinity for the biological and good stability. Whilegraphene is used as modifier for the study of chemically modified electrodes, theeffective surface area of the electrode and the current signal could be improvedSignificantly, the detection sensitivity could be extended, at the same time. In thisthesis, several kinds of modified electrode based on graphene were prepared, and theirapplications in research of fundamentals of electrochemistry were explored. Thedetails are listed below:Chapter one: based on the literature survey, the characteristics, preparation,application, preparation of chemically modified electrodes, applications of chemicalmodified electrode development of graphene were reviewed and the conception of thisarticle were presented.Chapter two: A graphene modified gold electrode (Gr/Au E) has been developedand it is used for the simultaneous determination of uric acid and dopamine with thepresence of Ascorbic acid. CV result shows that the electrode reaction of uric acid anddopamine could be catalyzed and anodic peaks could be separated by graphenemodified gold electrode. The differential pulse voltammetric results shows theresponse of the electrode was linear with the uric acid concentration in the range from30to1000μmol/L, and the dopamine concentration in the range from1.0to1000μmol/L. The graphene modified gold electrode has been successfully applied for thesimultaneous determination of uric acid and dopamine in urine.Chapter three: A novel gold nanoparticle and graphene modified electrode(Au/Gr/Au E) was prepared and it is used for the simultaneous determination of Rutin.CV result shows that the electrode reaction of rutin could be catalyzed and theoxidation and reduction peak current improved distinctly in the novel electrode. Onthe optimized of experimental conditions, the response of the electrode was linearwith the rutin concentration in the range from0.05-10μmol/L, with a detection limitof0.015μmol/L (S/N=3). The method was applied to the assay of rutin withsatisfactory results.Chapter four: A novel type of Nafion/graphene modified gold electrode(Nafion/Gr/Au E) has been developed and used for determination of Caffeine. CV result shows that the Oxidation peak current improved distinctly in the novel electrode,and the response of the electrode was linear with the caffeine concentration in therange from0.2-80μmol/L, with a detection limit of0.1μmol/L (S/N=3). The noveltype of electrode could be applied to the assay of caffeine in actual samples withsatisfactory results.