MICROPOROUS ALUMINUM-OXIDE FILMS AT ELECTRODES .7. MEDIATION OF THE CATALYTIC ACTIVITY OF GLUCOSE-OXIDASE VIA LATERAL DIFFUSION OF A FERROCENE AMPHIPHILE IN A BILAYER ASSEMBLY

Glucose oxidase was immobilized in the head group region of an organized bilayer self-assembled in a porous template of aluminum oxide film at a gold electrode. Immobilization of the enzyme involved interactions with the (ferrocenylmethyl) dimethyloctadecylammonium amphiphile, which forms the outer monolayer of the bilayer assembly. The same amphiphile mediates electrooxidation of glucose oxidase via lateral diffusion along the bilayer between the enzyme and the electrode surface. The enzyme immobilization does not restrict electroactivity of the ferrocene surfactant but it appears to bind ca. 60% of its population and thus restricts its participation in the electron transport process. These data lead to a postulate that the enzyme-surfactant interactions involve a much larger number of the ferrocene surfactant molecules than expected from the consideration of just electrostatic interactions. © 1990, American Chemical Society. All rights reserved.