Langmuir, Vol.19, No.23, 9580-9582, 2003
Selective noncovalent adsorption of protein to bifunctional metallic nanowire surfaces
Metallic nanowires composed of nickel and gold as well as bimetallic nickel-gold nanowires were fabricated via templated electrodeposition in nanoporous alumina membranes. Gold surfaces were functionalized with alkanethiols with terminal hexa(ethylene glycol) groups (EG(6)), while nickel surfaces were functionalized with palmitic acid, a 16-carbon fatty acid. When exposed to a fluorescently tagged protein, hydrophobic nickel wires exhibited bright fluorescence while EG(6)-terminated gold wires did not, indicating that the protein did not adhere to the EG(6)-functionalized nanowires. Nickel-gold nanowires presenting distinct segments of alkyl and EG(6) surfaces were also exposed to the fluorescent protein. Intense fluorescence was only observed on the nickel segment of these wires, demonstrating that proteins selectively adsorbed to one portion of these multicomponent nanostructures.