Electrochemically Active L-Cysteine Gold Modified Electrodes

Author(s)

de Oliveira, Fernando C. M. ^[1] ; Serrano, Silvia H. P. ^[2]

Affiliation

^[1] Univ Sao Paulo. Inst Chem

^[2] Univ Sao Paulo. Inst Chem

• Document type: Journal article
• Source: Electrochimica Acta; v. 125, p. 566-572, APR 10 2014.
• Web of Science Citations: 1

Abstract

Gold electrodes were easily modified using MPA (3- mercaptopropionic acid) to produce a self assemble monolayer, SAM, in which electrochemically active cysteine molecules were anchored to produce Au/MPA and Au/MPA/CSH electrodes. The functional groups, present on the modified electrode surfaces, were identified using cyclic voltammetry and ferricyanide ions, an electrochemical probe, at variable pH values. The steps which describe the global electrode process were identified and characterized using cyclic voltammetry. It involves the deprotonation of the R-SH superficial groups; production of R-S free radicals from R-S- electrochemical oxidation and attack and of R-S free radicals to the ASH adjacent molecules on the electrode surface, followed by the second electrochemical oxidation step to produce RSSR. The Au/MPA/CSH electrode showed electrocatalytic activity toward oxidation of quercetin in the range of 0.50 to 12.2 mu molL(-1) with a detection limit of 0.15 mu molL(-1). (C) 2014 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 09/18223-0 - Analytical potencialities of lignin derivatives from Kraft pulping (black liquors): extraction of heavy metals and development of voltammetric sensors
• Grantee: Silvia Helena Pires Serrano
• Support Opportunities: Regular Research Grants