Microscopic spots of glucose oxidase (GOx) were fabricated on platinum substrate electrode with a self-made concave platinum micrometer electrode. Firstly, the concave platinum micrometer electrodes were prepared by means of phenol-allylphenol copolymer insulation and electrochemical etching. Using concave platinum micrometer electrode as reference and counter electrodes and platinum substrate as a working electrode, GOx on the concave platinum electrode was then electrochemically deposited and fixed on a platinum substrate to form microscopic spots with biological activity by micro-decoration, based on the fact that GOx could be electrochemically deposited on the platinum electrode in a suitable condition (concentrations of GOx and Triton X-100, potential of electrode, etc.) due to the reduction of pH on the electrode surface. The GOx microscopic spots were characterized with scanning electron microscope and scanning electrochemical microscopy finally. The diameter of the microscopic spots fabricated by this method was about 20 μm, and the microscopic spots retained the biological activity. This approach of fabrication of GOx microscopic spots was simpler and had little interference.

Key words: scanning electrochemical microscopy, glucose oxidase, concave platinum micrometer electrode