Flexible glucose sensor with biocompatible polymer substrate

In this study, a flexible glucose sensor with biocompatible polymer substrate for biomedical measurement was constructed and tested. The sensor was constructed by immobilizing an enzyme to biocompatible polymer substrate with electrodes. In the fabrication of the sensor, Pt-working and Ag/AgCl-counter/reference electrodes were formed onto a flexible polymer substrate by MEMS technique. In the immobilization process of an enzyme, a mixture solution of glucose oxidase (GOD) and PMEH as a biocompatible polymer was spread onto the sensing region of the electrodes, thus obtaining the flexible glucose biosensor with biocompatibility. In the evaluation of the sensor characteristics, the sensor was dipped into a measurement cell filled phosphate buffer, and then a +400mV potential was applied to Pt-working electrode vs. Ag/AgCl-counter/reference electrode by potentiostat controlled by PC. Various concentrations of glucose solution were dropped into the beaker and the output current of the sensor was measured by PC via A/D converter. As a result of characteristics evaluation, the output current rapidly increased immediately after the drop of glucose solution and linearly corresponded to glucose concentration over a range of 0.05-4.0mmol/l, with a correlation coefficient of 0.999. The result suggests that GOD was successfully immobilized onto the substrate. This sensor would be applied to detecting tear glucose of rabbit for continuous evaluation of blood sugar level in the near future.