A polymer electrode in the form of a thin film was prepared by electrochemical copolymerization of 3-methylthiophene and thiophene-3-acetic acid. Glucose oxidase (GOx) was immobilized by covalent binding to the carboxyl groups on the electrode, and the GOx-immobilized electrode (GOx-electrode) was used as an anode in a glucose fuel cell. It was demonstrated by cyclic voltametry that in the presence of p-benzoquinone (BQ), which was adopted as an electron mediator, the GOx-electrode generated a significant glucose-oxidation current depending on the concentrations of both glucose and BQ. A large surface area of the GOx-electrode was considered to afford effective environment for the enzyme reaction and electron transfer. The fuel cell using the GOx-electrocle as an anode gave a power output of 42 mu W/cm(2)-anode at 30 degrees C, when its anodic compartment contained 100 mM glucose and 10 mM BQ. The performance of the cell was influenced by the concentrations of glucose and BQ in the anodic compartment. (c) 2007 Wiley Periodicals, Inc.