AMPEROMETRIC ENZYME ELECTRODE FOR SUCROSE DETERMINATION PREPARED FROMGLUCOSE-OXIDASE AND INVERTASE CO-IMMOBILIZED IN POLY(VINYLFERROCENIUM)

Co-immobilization of two enzymes, glucose oxidase and invertase, in po lyvinyl(ferrocenium) perchlorate (PVF+ClO4-) film led to the developme nt of a simple, sensitive, stable and low-cost sucrose sensor. Inverta se catalyses the conversion of sucrose to alpha-glucose and beta-fruct ose. Phosphate ions used in the medium catalyse the conversion of alph a-glucose to beta-glucose, eliminating the need for the commonly used third enzyme, mutarotase, for mutarotation. Glucose oxidase catalyses the oxidation of beta-glucose to gluconic acid, producing H2O2. Curren t due to H2O2 oxidation catalysed by PVF+ centres was measured, in con trast to most existing sucrose electrodes, which rely on measurement o f the O-2 reduction current.