Glucose oxidase membrane systems based on poly(vinyl chloride) matrices for glucose determination with an iodide ion-selective electrode

Abstract

Enzyme electrodes are described for the determination of glucose with an iodide-selective electrode. Glucose oxidase (E.C. 1.1.3.4) was immobilised in plasticised poly(vinyl chloride) either alone or with peroxidase (E.C. 1.11.1.7). Enzyme electrodes with only glucose oxidase in the membrane were used in conjunction with an ammonium molybdate catalyst to give graphs with a mean slope of 72 (s.d. = 3.2) mV decade^–1 of glucose with a lifetime of 3 d. Electrodes with membranes of glucose oxidase and peroxidase were of an improved quality with a mean slope of 74 (s.d. = 6.0) mV decade^–1 of glucose and a lifetime of 7 d. Comparison electrodes with membranes of glucose oxidase chemically immobilised with glutaraldehyde on bovine albumin gave a mean slope of 43(s.d. = 1.1) mV decade^–1 of glucose and a lifetime of >14 d.