Sod Modified Electrode Preparation And Electrochemical Behavior Of The Study

Ferrocene and SOD-ferrocene modified gold electrodes were made by crosslinkage method with fress egg white and glutaraldehyde. And cyclic voltammetry was performed to study electrochemical behaviors of modified electrodes in phosphate buffer solution of different pH values ,and in the presence of H2O2 .The results indicate that the electrochemical behaviors of ferrocene were stable when pH values from 2 to 7..While the peak currents of ferrocene began to decrease and decrease rapidly when pH > 9,This shows that the electrochemical property of ferrocene is prohibited in alkaline solution .The results of the modified electrode in phosphate buffer containing H2O2 indicates that the peak currents of ferrocene modified electrode decreas with the addition of H2O2 ,and the higher the concentration of H2O2 the more manifestly decrease of the peak currents of ferrocene,but the ferrocene was not lost during the reaction . The peak currents of SOD-ferrocene modified electrode did not decrease in low concentrations of H2O2 , because SOD can react with H2O2 and made the concentration of H202 lower than that of before .But with the increase of the concentrations of H2O2 ,the peak currents of the modified electrode began to decrease too when the concentrations of H2O2 are high enough.So we conclude that ferrocene (III) could be catalyst to the decomposition of HjOa.and SOD can prohibit the decrease of the ferrocene peak current.Cyclic voltammetry and Chronocoulometry were also used to study the adsorption behaviors of cysteine and homocysteine in phosphate buffer solution or in ImM HClO4 solution.The results indicate that cysteine and homocysteine can be adsorbed strongly on gold electrode,and make use of this properity we make SAM modified electrode withHomocysteine.Moreover we make SOD modified electrode with EDC on the SAM modified electrode.The electrochemical behaviors of the SAM-SOD modified electrode show that homocysteine can promote the electron transfer of SOD and make the direct electrochemistry of SOD come true.