A composite clay glucose biosensor based on an electrically connected HRP

A novel bienzyme electrode based on a redox clay matrix is described for th e cathodic detection or glucose. Peroxidase (HRP) was immobilized in clay m atrix containing graphite particles. In order to electrically connect the i mmobilized HRP, electropolymerized films of 3.4-dihydroxybenzaldehyde were generated within the composite matrix. The resulting biosensors were applie d to the amperometric detection of H2O2 via its electroenzymatic reduction at 0V (vs. SCE). The influence of the biosensor composition on the efficien cy of H2O2 detection was investigated the highest sensitivity bring 130 mAM (-1) cm(-2). The additional immobilization of glucose oxidase in an externa l clay gel led to a bienzyme electrode for the determination of glucose; th e highest sensitivity being 14.95 mAM (1)cm(-2).