Electrodeposition of redox polymers and co-electrodeposition of enzymes by coordinative crosslinking

Abstract

Thin films of transition metal complex-based redox polymers are electrodeposited on electrodes. When hydrated, an electrodeposited film conducts electrons by electron exchange between backbone-bound, but mobile, functional segments of its redox polymer constituents. These functional segments, or redox complexes, have labile ligands in their inner coordination spheres. The backbones of the redox polymers have strongly coordinating ligands. Electrodeposition results from coordinative crosslinking by exchange of labile ligands and strongly coordinating ligands between polymer chains. When a biological macromolecule or protein, such as a redox enzyme, is added to the solution from which the redox polymer is electrodeposited, it is co-electrodeposited on the electrode surface. When the co-deposited film contains redox enzymes, for example, the modified electrode may be used to catalyze the electrooxidation or electroreduction of substrates of the enzymes. Electrodes modified according to the invention also have application in chemical or biological assays.