The Electrocatalytic Oxidation Of Reduced Glutathione In The Modified Carbon Paste Electrodes

Glutathione (GSH) consists of glutamic acid (Glu), cysteine(Cys) and glycine (Gly) composed of bioactive compounds tripeptide which contains thiol, The content change of GSH in the organism is an important health index in clinical medicine and also a critical biological identification material. It has been well founded that a change in GSH concentration may be correlated with aging and pathogenesis of several diseases, including Alzheimer disease, Parkonson’s, rheumatoid arthritis, muscular dystrophy, cardiovascular disease, cervical cancer and liver disease. Because the nature of GSH is active and easy to be oxidized, it’s necessary to develop simple and effective methods for the quantitative determination analysis of GSH. This thesis will elaborate on five aspects of electrochemical methods for GSH:Chapter 1 Introduction:The nature and function of GSH were outlined, the methods of its determination and the research of its analytical method as well as the research status and development tendency were also reviewed. Then we introduced the chemical modified electrodes of the types, preparation methods, electrode performance characterization and some modified materials of modified electrode in brief. Finally the research contents and significance of this paper were summarized.Chapter 2:The preparation of a new type of Acetylene black (AB) modified carbon paste electrode, which using cyclic voltammetry in PBS solution pH 7.0 with Rutin for catalytic oxidation of GSH. Under the optimal experimental conditions, cyclic voltammetry (CVs), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), Tafel (Tafel), differential normal pulse voltammetry (DNPV) on the characterize of the modified electrode and the electrochemical behavior of GSH were determined. The proposed method was successfully applied to the determination of GSH in actual samples.Chapter 3:The tyrosine as electrocatalysis medium on kaolin modified carbon paste electrode for the electrochemical behavior of GSH were explored. At the same time, cyclic voltammetry (CVs), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), Tafel (Tafel), differential normal pulse voltammetry (DNPV) process and the kinetic parameters of GSH on the modified electrodes were studied. The proposed method was used to determine GSH in urine.Chapter 4:Nickel hydroxide and multi-walled carbon nanotube composite particles (Ni(OH)2-MWCNTs) were synthesised by nature sedimentation method and it was applied to modify carbon paste electrode. Vanillin(Val) as a new mediator was used to determine glutathione on the modified electrode. The differential pulse voltammetry was established the oxidation peak current and the relationship with the concentration. The proposed method was rapid and sensitive, and developed for the determination of GSH in actual cucumber samples.Chapter 5:The new modified electrodes by cuprous oxide/graphene composite particles modified carbon paste electrode (Cu2O/GNs/CPE) to electrochemical determination of GSH were explored, cyclic voltammetry (CVs), electrochemical impedance spectroscopy (EIS), timing coulomb method (CC) and differential pulse voltammetry (DPV) were used to the quantitative analysis of GSH, the rapid and sensitive analysis method was established for the concentration of GSH in actual tomato samples.