AMPEROMETRIC MICRO-BIOSENSOR ARRAY FOR CHOLINE AND ACETYLCHOLINE BASED ON A GLASSY CARBON ELECTRODE MODIFIED BY PLATINUM-BLACK PARTICLES AND A CO-CROSSLINKED ENZYME SYSTEM

Abstract

A glassy carbon electrode was first modified by electro-depositing sub-micrometer platinum black particles on the surface. An acetylcholine micro-biosensor array and a choline micro-biosensor array were fabricated based on immobilization of acetylcholineasterase-choline oxidase or choline oxidase by cross-linking with glutaraldehyde on the Pt-black/GCE. Significant enhancement in performances of these biosensors was achieved. The chronoamperometric response of the acetylcholine micro-biosensor array gave a linear relation in the range of 29 to 1200μmol/L and a detection limit of 8.7μmol/L acetylcholine. The amperometric response of the choline micro-biosensor array gave a linear relation in the range of 24 to 1000μmol/L and a detection limit of 7.4μmol/L choline. They also possessed very good stability and reproducibility for long-term use.

Keywords:

• Choline
• Acetylcholine
• Amperometry
• Micro-biosensor array
• Platinum-black
• Choline oxidase
• Acetylcholineasterase

ACKNOWLEDGMENTS

The authors gratefully acknowledge financial support from the Chinese Academy of Sciences (Grant No. 9002KJ951-A1-507) and special financial support from the USTC.