Amperometric glucose biosensor based on a tetrathiafulvalene‐mediated epoxy‐graphite biocomposite

An inexpensive, robust, and easily mechanized amperometric glucose senor based on a biocomposite material has been constructed. The biocomposite is made of graphite, a nonconductive epoxy resin, tetrathiafulvalene (TTF) as a redox mediator, and glucose oxidase (GOD). The enzyme retains its bioactivity on confinement in the rigid epoxy‐graphite matrix, with the oxidation current of the reduced mediator serving as the analytical signal (at 150 mV [vs. Ag/AgCl] in a pH 7.00 buffered solution featuring 0.1 M phosphate and 0.1 M KC1). The resulting biosensor shows a linear response in the 0.1 to 2 mM glucose range and produces a steady‐state signal within a few seconds (11 seconds for a 95% response). Simple polishing procedures can be used to regenerate a freshly bioactive transducer surface. Copyright © 1994 VCH Verlagsgesellschaft mbH