Design and properties of photocurable electroconductive polymers for use in biosensors

The authors report preparation of a new hydrophilic photocurable electroconductive polymer to be used as a matrix for an enzyme based biosensor. Polymers, prepared by radical terpolymerization, consisted of N,N-dimethylacrylamide (DMAA) as the water soluble part, m-azidostyrene (AzSt) as the photochemically active center to entrap an enzyme and to fix it on an electrode, and vinylferrocene (VFe) as the charge transfer mediator between an enzyme and an electrode. Ultraviolet light (UV) irradiation to the terpolymer coated on a carbon electrode produced a water swellable cross-linked polymer that was chemically fixed on a carbon electrode. Cyclic voltammetry on a hydrogelated electrode in a phosphate buffered solution exhibited single oxidation/reduction reproducibly, indicating that the formed conducting hydrogel was stable. An increase in VFe content and a decrease in AzSt content of a terpolymer resulted in larger electrochemical responses on normal pulse voltammetry. When glucose oxidase was immobilized in a hydrogel, a dose dependent electrochemical response to glucose was observed.