CHARACTERIZATION OF COMPOSITE MEMBRANE OF POLY(VINYL ALCOHOL) AND REGENERATED SILK FIBROIN FOR IMMOBILIZATION OF HORSERADISH-PEROXIDASE ANDAN AMPEROMETRIC NECKELOCENE-MEDIATED SENSOR SENSITIVE TO HYDROGEN-PEROXIDE

Horseradish peroxidase (HRP) was effectively entrapped in a novel comp osite membrane of poly(vinyl alcohol) and regenerated silk fibroin. IR spectroscopy was employed to characterize the structure of the compos ite membrane and scanning electron microscopy was used to visualize th e morphology of the composite membrane. HRP was utilized to amplify th e amperometric response of the sensor by catalyzing reduction of hydro gen peroxide via nickelocene, an electron transfer mediator between im mobilized HRP and a glassy carbon electrode. The influence of various experimental parameters such as pH, temperature and applied potential were explored for optimum analytical performance. The sensor possessed a variety of characteristics including good sensitivity, rapid respon se time and a low detection of limit of 0.1 mu mol dm(-3), which arose from the efficiency of electron transfer between immobilized HRP and the electrode via nickelocene.