Electrochemical oxidation of L-cysteine mediated by a fullerene-C 60-modified carbon electrode

Abstract

Use of a glassy carbon electrode modified by adhered microcrystals of fullerene-C60 mediates the oxidation of cysteine in the presence of aqueous potassium-containing electrolytes. Under conditions of cyclic voltammetry, the potential for the oxidation of cysteine is lowered by approximately 100mV and current is enhanced significantly relative to the situation prevailing when a bare glassy carbon electrode is used. Additional mediation occurs when the potential range covered includes that of C 60/C60n- redox couples. The sensitivity under condition of cyclic voltammetry is significantly dependent on pH, temperature and C60 dosage. Excellent analytical and/or recovery data are obtained with vitamin pill, cassamino acid (hydrolyzed casein) and for a range of beverages. © 2003 Elsevier B.V. All rights reserved.