Preparation of Thin Protein Membranes by the 'Electrochemically Controlled Adsorption and Its Application

Abstract

Electrochemically controlled adsorption of an enzyme to solid electrode surface was applied to form functional thin protein membranes. Glucose oxidase (GOD) was adsorbed on a platinum electrode surface at a controlled potential in an aqueous solution. Adsorbed GOD was quantitatively analized by the fluorescent method. The GOD-adsorbed electrode was assayed for its enzyme activity by colorimetry. It was found that GOD adsorption and the enzyme activity of the GOD-deposited electrode were controllable by the adsorption potential. Thin protein molecular membranes were formed on the platinum surface in the surface coverage ranging from 3 to 4. Enzyme activity of a GOD-adsorbed electrode also depended on pH of the electrolyte solution for electroadsorption and reached optimum at pH 3. Furthermore, GOD-electrochemically deposited platinum electrode was applied to an amperometric sensor for glucose. The sensor showed rapid response (2s).