An inexpensive, robust, polishable and easy to mechanize amperometric transducer showing a long lifetime, based on a composite material made of graphite and non-conducting epoxy resin (Epo-Tek H77), was constructed. This composite was characterised electrochemically using cyclic voltammetry and linear-sweep voltammetry. The applicability of this amperometric transducer was demonstrated in the construction of a glucose biosensor based on the amperometric detection of hydrogen peroxide produced by the catalytic action of glucose oxidase covalently immobilized on a nylon mesh. The sensor shows a linear response range for glucose in the range 10-5-10-2 M when a potential of 1150 mV is applied with respect to an Ag/AgCl electrode in a pH 7.00 buffered solution with 0.1 M phosphate and 0.1 M KCl. The resulting biosensor was compared with a commercial glucose analyser. © 1993.
- Enzymatic methods
- Enzyme electrodes
- Epoxy-graphite composite electrode