Conductive diamond nanowires, fabricated by maskless oxygen plasma etching of highly boron-doped polycrystalline diamond substrates, were decorated with nickel nanoparticles. The nickel modified boron-doped diamond nanowire (Ni-BDD NWs) electrodes were prepared through cathodic reduction of nickel sulfate in PBS (pH 6.5) followed by cycling in KOH to oxidize remaining metallic Ni deposits into Ni(OH)(2). The novel electrode allowed for orientation-controlled immobilization of histidine-tagged peptides without need for surface linking with any other ion-chelating compound. (C) 2012 Elsevier Ltd. All rights reserved.