A Novel Amperometric Hydrogen Peroxide Biosensor Based on Catalase Immobilization on Poly(glycidyl methacrylate-co-vinylferrocene)

A novel amperometric hydrogen peroxide biosensor was fabricated for the determination of H2O2. Catalase (Cat) was immobilized on a glassy carbon electrode by poly(glycidyl methacrylate-co-vinylferrocene) (poly(GMA-co-VFc)). A polymeric electron transfer mediator, containing copolymers of glycidyl methacrylate (GMA) and vinylferrocene (VFc) with different molar ratios, have been prepared by free radical copolymerization. Amperometric response was measured as a function of concentration of H2O2, at fixed potential of +0.35 V vs. Ag/AgCl in a phosphate buffered saline (pH 7.5). The mediated hydrogen peroxide biosensor had a fast response of less than 7 s with linear range 0.5-14 mM. The sensitivity of the biosensor for H2O2 was 34 nA/mM.cm2.