CHARACTERIZATION OF REGENERATED SILK FIBROIN MEMBRANE FOR IMMOBILIZING PEROXIDASE AND CONSTRUCTION OF AN AMPEROMETRIC HYDROGEN-PEROXIDE SENSOR EMPLOYING PHENAZINE METHOSULFATE AS ELECTRON SHUTTLE

Regenerated silk fibroin prepared from waste silk was used for the fir st time as the immobilization matrix of peroxidase. The structures of the blend membranes of regenerated silk fibroin and peroxidase were in vestigated using IR and scanning electron microscopy. It was found tha t the two macromolecules were immiscible despite their intermolecular interactions. An amperometric H2O2 sensor using phenazine methosulphat e as the electron transfer agent between horseradish peroxidase in a r egenerated silk fibroin membrane and glassy carbon electrode was fabri cated. The sensor was highly sensitive to H2O2 with a detection limit of 1.0 X 10(-7) M H2O2 and a response time of less than 5 s. The effec t of the applied potential and the mediator concentration on the Micha elis-Menten constant was calculated, and the influence of various expe rimental parameters such as pH, temperature, applied potential and the mediator concentration was investigated for optimum analytical perfor mance.