Electrochemistry study of sulphonated ferrocenes as redox mediators in enzyme electrodes

E. LIAUDAT; FERNANDO BATTAGLINI; ERNESTO J. CALVO

JOURNAL OF ELECTROANALYTICAL CHEMISTRY

Elsevier

Lugar: Amsterdam; Año: 1990 vol. 293 p. 55 - 68

0022-0728

The electrochemical oxidation of mono and disulphonic derivatives of ferrocene (dicyclopentadienyliron) to ferricinium was studied by cyclic voltammetry in aqueous solutions. Both redox systems show fast electrode kinetics on gold, platinum and carbon electrodes. As expected, the sulphonic derivatives are more oxidant than the unsubstituted ferrocene. Ferrocene sulphonates are efficient electron mediators in redox enzyme catalysis for the anaerobic oxidation of glucose catalyzed by glucose oxidase (GOD). The second order rate coefficients for the oxidation of reduced GOD (FADH2), k, are 9.5 × 104 and 9.0 ×103 1 mol−1 s−1 respectively, for mono and disulphonic derivatives at pH 4.7. Due to the increased solubility of sulphonic derivatives, the complete redox-enzymatic kinetic analysis can be made.