Use of surfactant-modified cellulose acetate for a high-linearity and pH-resistant glucose electrode

Abstract

Cellulose acetate modified by incorporation of the surfactant Tween-80 is used as an outer membrane in a glucose oxidase based enzyme electrode. The membrane acts as a glucose diffusion restricting barrier, allowing extension of response linearity to 0.4 mol I^–1, with sensitivity of 2.5 nA l mmol^–1. Response times of <100 s can be achieved by use of initial slope (I/t) measurements. The membrane also provides protection for the enzyme from low pH deactivation for at least 10 min, allowing for re-use in low-pH samples such as citrus fruit.