The direct electrochemistry of cytochrome c at a hanging mercury drop electrode modified with 6-mercaptopurine

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 451; no. 1; pp. 89 - 93
• Main Authors: Sevilla, J.M, Pineda, T, Román, A.J, Madueño, R, Blázquez, M
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.1998; Elsevier Science
• Subjects: 6-Mercaptopurine; Biological and medical sciences; Cytochrome c; Electrochemistry; Fundamental and applied biological sciences. Psychology; Mercury electrode; Molecular biophysics; Physical chemistry in biology; Cytochrome c; Electrochemistry; 6-Mercaptopurine; Mercury electrode; Hemoprotein; Thiol; Dropping electrode; Bioelectrochemistry; Electron transfer; Acetic acid; Electrochemical reaction; Buffer solution; Mercury; Modified material
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/S0022-0728(98)00075-8

The modification of a mercury electrode with 6-mercaptopurine (6MP) has been performed at pH 6 in acetate buffer and the electrode behaviour has been checked in the absence of the modifier in solution. Direct electrochemistry of cytochrome c has been observed on a 6MP-Hg modified electrode. At high coverage of 6MP, the monolayer acts as an effective promoter for the redox exchange of cyt c, which is not observed on a bare mercury electrode. The film is stable for more than 200 scans and must play a role on avoiding irreversible adsorption and denaturation of the protein. At pH 7, 25 mM phosphate buffer and 0.1 M NaClO 4, cyt c exhibits a quasi-reversible electron exchange similar to that reported with gold modified electrodes, the electron rate constant being 4.1×10 −3 cm s −1. As far as we know it is the first time that such a response has been observed on mercury.