Flow injection based renewable electrochemical sensor system.

A novel class of electrochemical sensors is proposed utilizing electrically conducting beads to form a disposable electrode as well as nonconducting beads to form renewable layers of immobilized enzymes. The concept, aimed to prevent fouling, is tested on an amperometric sensor coupled to nonconducting beads with different immobilized oxidases:  galactose, lactate, alcohol, or glucose oxidase, the latter two being used to determine alcohol and gluocse, respectively, in samples of beer and wine. Glucose oxidase was also immobilized on conducting glassy carbon particles to explore the performance of a biosensor where both enzyme and electrode can be automatically renewed in less than 1 min. The results confirm that the concept of a flow injection renewable electrochemical sensor (FI-RES) is practical. It provides a novel approach to biosensing, to comparing enzyme activity, to studying enzyme immobilization on different supports, and to voltammetry in general.