The Bioelectrochemistry Study Of Cysteine And Seleno-cystine

Biologically important Seleno-cystine(SeC) and Cysteine(CySH) have electrochemical activity. The electrochemical behavior of SeC and CySH and SeC interaction with riboflavin are investigated. It can not only help to understand the biological electron transfer process of seleniferous and sulfur-containing amino acids, but also supply significant information of structure and function in organism.The electrochemical behavior of SeC on Se-Au film modified glassy carbon electrode is studied with cyclic voltammetry. It's showed that SeC have two cathodic peaks and one anodic peak at -576mV, -870mV and -327mV, respectively. Effects of such conditions as deposition time, deposition potential, the form of film, scan rate and scan time on peak current have been investigated. Chemometrics methods are used to deal with the experimental processes and data. Study of the electron transfer reactions can provide information about Se-Au film catalysis of the redox reaction of SeC.Using self-assembling(SA) method to prepare SeC modified gold electrode (SeC/Au), the difference of interaction between riboflavin and arrayed SeC SA film is compared with those in solution. The anti-oxidation function of SeC is studied, which show the S A film of SeC/Au can stave the redox reaction of riboflavin.CySH modified silver electrode is prepared by SA, and its application in adsorption voltammetry analysis of Cu( II) and Sn( II) is presented. Cu( II) and Sn( II) can be detected by the cathodic current using adsorptive voltammetry. The determination of Cu(II) and Sn(II) are in the range of 5.0X 10-9-5.0X 10-4mol/L and 5.0 X 10-10-5.0X 10-6mol/L, respectively. The detection limits for Cu(II) and Sn(II) are 1.0 X 10-9 mol/L and 1.0 X 10-10 mol/L, and the RSD are 4.9% and 1.1%, respectively. The method has been used for the determination of Cu(II) in Cola samples and Sn( II) in plastic samples with satisfactory results .