IMMOBILIZATION OF HORSERADISH-PEROXIDASE ONTO A COMPOSITE MEMBRANE OFREGENERATED SILK FIBROIN AND POLYVINYL-ALCOHOL AND ITS APPLICATION TOA NEW METHYLENE BLUE-MEDIATING SENSOR FOR HYDROGEN-PEROXIDE

Horseradish peroxidase (HRP) was effectively in a novel composite memb rane of polyvinyl alcohol (PVA) and regenerated silk fibroin (RSF). IR and scanning electron microscopy were employed to provide a useful in sight into the structure and morphology of the immobilized HRP composi te membrane. A new methylene blue-mediating sensor for hydrogen peroxi de was constructed which was based on the composite membrane as an imm obilization matrix for HRP. Cyclic voltammetry and amperometric measur ements were used to demonstrate the efficiency of the new methylene bl ue mediating an electron transfer between the immobilized HRP and a gl assy carbon electrode in bioelectrocatalytic reduction of hydrogen per oxide. Performance and characteristics of the sensor were evaluated wi th regard to response time, detection limit, selectivity, and dependen ces on temperature and pH as well as operating and storage stabilities . The sensor has a variety of characteristics including good sensitivi ty, rapid response time, and low detection limit of 5.0 mu M. (C) 1997 Elsevier Science Inc.