ELECTRICAL COMMUNICATION OF POLYETHYLENE GLYCOL-MODIFIED GLUCOSE-OXIDASE IN CARBON-PASTE AND ITS APPLICATION TO THE ASSAY OF GLUCOSE

An amperometric enzyme electrode was constructed by making use of poly ethylene glycol-modified glucose oxidase (PEG-GOD) as a catalyst and c arbon paste (CP) as a matrix. The electrode retained an enzyme activit y of 20 MU cm-2, which was higher than the CP containing unmodified GO D electrode. Electrical communication, i.e., electron transfer between the modified GOD and the CP matrix, was observed on the differential pulse voltammograms. The oxidation current of the CP/PEG-GOD electrode was increased by addition of glucose to a solution at the applied pot ential of 0.10 V versus Ag/AgCl and was proportional to the glucose co ncentration up to 50 mM. CP/PEG-GOD was stable for a week, which was n ot improved by the modification of enzyme.