Glucose oxidase (GOx) was immobilized on the electrode surface of multi-walled carbon nanotubes

amino functionalized carbon nanotubes (AMWNTs) and carboxyl functionalized carbon nanotubes (MWNTs-COOH). Electrochemical measurements indicated that the formal potentials of GOx immobilized on AMWNTs and MWNTs-COOH did not change

but their peak currents were improved. The peak current of GOx immobilized on AMWNTs was four times larger than that immobilized on MWNTs. The electrochemistry behavior of Nafion/GOx-AMWNTs/GC electrode were further characterized. The results indicated that GOx immobilized on AMWNTs could undergo a direct quasi-reversible electrochemical reaction and show good stability. Amino-functionalized electrodes could significantly improve the performance of GOx-based biofuel cells.