S. Gondo et al., IMMOBILIZATION OF 2 ENZYME-SYSTEM OF GLUC OAMYLASE AND GLUCOSEOXIDASEONTO PLATINUM-ELECTRODE AND ITS CHARACTERISTICS AS MALTOSE SENSOR, Kagaku kogaku ronbunshu, 21(2), 1995, pp. 306-311
Amino groups were attached to a platinized platinum electrode through
alkylamine-silanization. Glucoamylase (GA) and glucoseoxidase (GOD) we
re then immobilized directly onto the platinum electrode. The immobili
zed two enzyme electrode (GA-GOD-Pt) was coupled with a Ag/AgCl electr
ode as its counter electrode and its characteristics as a maltose sens
or were investigated. An increased linearity was observed as the pH va
lue of the ambient solution increased. Its tendency of increased linea
rity with increased pH value toward 7.5 was examined through the aid o
f theoretical analysis of the relation between electrode current and m
altose concentration and the use of the GA-GOD-Pt electrode under cond
itions of somewhat depressed GA activity was recommended. The dynamic
response of the GA-GOD-Pt to the stepwise change of maltose concentrat
ion was found to be expressed by a first order response model without
time delay.