PREPARATION OF COMPOSITE CONSISTING OF PO LYPYRROLE AND POLY(VINYL ALCOHOL) INCLUDING GLUCOSE-OXIDASE AND ITS APPLICATION TO GLUCOSE SENSOR

Glucose sensing with an electrode modified with poly(vinyl alcohol) (P VA) including glucose oxidase (GOD) and polypyrrole (PPy) was discusse d. PPy/PVA/GOD composites were prepared on an electrode spincoated wit h PVA/GOD film by electropolymerization of pyrrole. Effects of the thi ckness of PVA/GOD film and the content of GOD in the film on growth of PPy was investigated by chronoamperometry and scanning electron micro graphy. It was found that the presence of GOD in the film led to accel eration of the polymerization of pyrrole and morphology of the PPy/PVA /GOD film. The activity of GOD was found to be independent of the film thickness. This result suggests that the enzyme reaction of GOD immob ilized on the surface of the PPy/PVA/GOD film contributed to the curre nt response to glucose. The current based on the reaction of GOD with glucose decreased rapidly with an increase of the film thickness on th e electrode. It is considered that the electrons arising from the enzy me reaction were easily trapped in the PPy/PVA/GOD film due to an incr ease of the film thickness.