AMPEROMETRIC GLUCOSE BIOSENSOR BASED ON AN ELECTROCATALYTICALLY BULK-MODIFIED EPOXY-GRAPHITE BIOCOMPOSITE

An inexpensive, robust, polishable and easily machinable amperometric glucose transducer was constructed. The biocomposite materials used were graphite, palladium-gold, non-conducting epoxy resin and glucose oxidase. The enzyme retains its bioactivity in the rigid epoxy-graphite matrix. The electrocatalytic oxidation of hydrogen peroxide is enhanced by gold-palladium and it is used as the analytical signal (at 900 mV vs. Ag/AgCl in a pH 7.00 buffered solution with 0.1 M phosphate and 0.1 M KCI). The biosensor exhibits a linear response to glucose in the 0.01-2 mM range and produces steady-state signals within a few seconds (6 s for 95% signal). Simple polishing procedures can be used to generate a fresh bioactive transducer surface.