High efficiency of electroplating Ni-Co nanowires upon the capture of immobilization of histidine-tagged protein

A Ni-Co compound (9:1) alloy of nanowires (NWs) synthesized by TiO₂ nanotube templates was treated by N₂/H₂ annealing to enhance the immobilization of penta-histidine-tagged (5 x His-tagged) biotin. Based on the theory of immobilized metal affinity chromatography (IMAC), the chelator of transition, including Ni⁺² and Co⁺² metallic ions, was used to capture the 5 x His-tagged biotin by nanowire structure in this study. Physical properties and electrical resistivity in one dimension of annealed Ni-Co alloy NWs were characterized and then, the protein capture efficiencies were observed by measuring fluorescence intensities. By appropriate treatment on metallic Ni-Co NWs ligand surfaces, it was found that lower electrical resistivity combined with a higher saturation magnetic flux density (Bs) may be useful for immobilizing 5 x His-tag biotins. Furthermore, there is not only a higher contact probability but the surface-to-volume ratio of one dimensional Ni-Co alloy NW ligands proposes higher detected fluorescence sensitivity than that of Ni-Co film.