VOLTAMMETRY OF COVALENTLY IMMOBILIZED CYTOCHROME-C ON SELF-ASSEMBLED MONOLAYER ELECTRODES

Cytochrome c was covalently immobilized on carboxylic acid terminated self-assembled monolayer gold electrodes via electrostatically guided carbodiimide coupling. Covalently immobilized cytochrome c was found to be stable, electroactive, and functional. Cyclic voltammetry revealed an electroactive coverage corresponding to ca. one-third monolayer and a surface formal potential slightly negative of the value obtained for electrostatically adsorbed cytochrome c. Electron transfer kinetic results suggest that covalently immobilized and electrostatically adsorbed cytochrome c are similarly oriented at the electrode surface.