Electron transfer function of kerateine gel and conjugated redox reaction by using the kerateine-immobilized membrane

Kerateine gel, prepared by reducing wool keratin with alkaline 2-mercaptoethanol-urea solution and by partially reoxidizing the dissolved kerateine, reduced iron(III) to iron(II). Reduction of iron(III) was enhanced by addition of copper(II). Reduction of methylene blue (MB) to leuco MB with thioglycollic acid (TGA) as a model compound of wool thiol group was investigated in the presence of copper(II) and intercuticular cementing material (δ_Cu) extracted from wool fiber. It is confirmed that copper(II) is a catalyst for the reduction of MB and the δ_Cu containing copper ion acts as a carrier for electron transfer. Some kerateine/δ_Cu-immobilized hydrophilic polyurethane membranes were prepared. A conjugated redox reaction combining the reduction of MB and the oxidation of TGA was carried out across these membranes.