Protein layer coating method on metal surface by electrochemical process through genetical introduced tag.

The technology of mercaptide self-assembly has previously been used to coat proteins onto metals, but is not practical for many surfaces. In this study, a short peptidic tag was employed for the electrochemical immobilization of proteins on metals (ECtag). A 6-mer histidine (alpha-amino-1H-imidazole-4-propionic acid) homopeptide was employed as an ECtag ligand, which forms coordinate bonds with Ni2+ and other divalent metal ions. Protein A was chosen as a model protein for the immobilization, and was genetically tagged with an ECtag for immobilization onto a Pt electrode surface through the reduction of ECtag:Ni2+ to ECtag:Ni by the electrode potential.