Inosine Sensor Based on an Amorphous Silicon Isfet

Abstract

Abstract A sensor for the determination of inosine was prepared by a combination of the enzyme system (shown below) and an amorphous silicon ISFET (a-ISFET). Nucleoside phosphorylase and xanthine oxidase were covalently immobilized on polyvinylbutyral membrane containing 1, 8-diamino-4-aminomethyloctane. The optimum conditions for determination of inosine were pH 7.5, 32[ddot] C. The sensor gave a linear relationship between the initial rate of the output gate voltage change and the logarithm of inosine concentration between 0.02 and 0.1 mM. Determination of inosine was possible within 7 min. The system could be used for two weeks with about 35% loss of enzymatic activity.