Study on the ET Process of SOD at Cysteine Modified Gold Electrode

Abstract

Cysteine-modifed gold wire electrode was used for the first time to examine the promoted electron transfer process of superoxide dismutase. Electrochemical Quartz Crystal Microbalance technique was combined with cyclic voltammetric study for the understanding of coupled adsorption/desorption process of different states of SOD molecules.

One-step method embedding superoxide dismutase and gold nanoparticles in silica sol–gel network in the presence of cysteine for construction of third-generation biosensor

“…A pair of redox peaks was observed at the SOD/Cys/Au (Fig. 2(a)), which was in agreement with the previous results (Wu et al, 1999;Tang et al, 2004b). When the GNPs were introduced by adsorption, the responses of SOD/GNP/Cys/Au were largely increased ( Fig.…”

“…There are three main ways to construct the third-generation superoxide anion biosensors based on SOD. The first method is based on the promoters (e.g., mostly mercaptopropionic acid and cysteine) by using a self-assembled monolayer (SAM)-modified electrode (Wu et al, 1999;Meng et al, 2001;Tang et al, 2002Tang et al, , 2004aTian et al, 2002). SAMs can potentially provide a reproducible and robust method of fabricating immobilized enzyme layers where some control over the orientation and distribution of the enzyme is afforded (Gooding and Hibbert, 1999).…”

A carbon fiber microelectrode-based third-generation biosensor for superoxide anion

“…This demonstrates that the observed CV response corresponds to the electrode reaction of Cu, Zn-SOD confined on the Cys/Au/CFME. These properties are quite similar to those observed with conventional Au electrodes modified with SAM of cysteine reported in earlier work (Tian et al, 2002a;Wu et al, 1999), suggesting that the present protocol based on electrodeposition of Au nanoparticles on the CFME to form a SAM of cysteine to confine SOD stably and more importantly, to facilitate the direct electrochemistry of SOD is very effective for constructing the CFME-based third-generation O 2…”

Electrochemical Detection and Sensing of Reactive Oxygen Species

“…In addition, the reversible electrochemical redox response of bovine and human copper-zinc SODs at a gold electrode in the presence of various promoters for facilitation of the direct electron transfer was also observed by Borsari, Azab, and their coworkers [68,69] and Wu et al [70,71]. The electron transfer between a glassy carbon electrode and polyethylene oxide-modified SOD was successfully accomplished by Ohsaka et al using methyl viologen as an interesting redox mediator [72].…”