HYDROGEN-PEROXIDE AMPEROMETRIC BIOSENSOR BASED ON A PEROXIDASE-GRAPHITE-EPOXY BIOCOMPOSITE

An amperometric biosensor sensitive to hydrogen peroxide has been buil t, using a HRP-graphite-epoxy biocomposite. The proximity of the redox centers of the enzyme and the conductive sites at the surface of the electrode permits a direct regeneration of the enzyme. The response ch aracteristics of this biosensor have been improved by adding powdered platinum to the matrix of the biocomposite. When Pt is absent, the wor king potential is -300 mV vs. Ag/AgCl and the response is linear betwe en 0.03 mM and 7 mM. When 3% wt platinum is added to the biocomposite, a stable response is produced at -50 mV vs. Ag/AgCl and the linearity range lies between 0.09 mM and 9 mM. The response time is approximate ly 2 s for both the cases.