Feature of an amperometric ferrocyanide-mediating H2O2 sensor for organic-phase assay based on regenerated silk fibroin as immobilization matrix for peroxidase

Peroxidase was immobilized in the regenerated silk fibroin membrane prepared from waste silk and the structures of the blend membranes of regenerated silk fibroin and peroxidase were investigated with ir and scanning electron microscopy, indicating that the two kinds of macromolecules were immiscible and their intermolecular interactions existed in the blend membrane. Cyclic voltammetry and constant applied potential measurements tested the catalytic activity of the immobilized peroxidase in water-iso-propyl alcohol system by employing ferrocyanide as an electron transfer mediator between the enzyme and a glassy carbon electrode. Regenerated silk fibroin coating appeared very attractive for entrapping the enzyme onto the electrode since the immobilized peroxidase showed long-term stability in the organic media.