Glucose Biosensor Based on a Sol-Gel-Derived Platform

Sol-gel-derived glasses have emerged as a new class of materials well suited for the immobilization of biomolecules. As a consequence, they are also finding new applications as platforms for chemical sensors. Room temperature (or lower) processing conditions, chemical inertness, negligible swelling effects, tunable porosity, and the high purity of sol-gel-derived glasses make them ideal for many types of sensor applications. We report here on the characterization of tetraethyl orthosilicate(TEOS-) derived thin sol-gel films, doped with glucose oxidase (GOx), as a sensing platform for a prototypical biosensor. GOx was immobilized in/on a thin TEOS sol-gel film using physisorption, microencapsulation, and a new sol-gel:GOx: sol-gel sandwich configuration. Amperometric and photometric detection modes are used to study the response profiles and in turn quantify glucose. The results clearly demonstrate that the sandwich configuration exhibits a fast response and high enzyme loading. This particular scheme is stable for at least 2 months under ambient storage conditions.