Metal microelectrode nanostructuring using nanosphere lithography and photolithography with optimization of the fabrication process

Nanostructured metal microelectrodes were fabricated using a combination of nanosphere lithography, conventional photolithography and physical vapour deposition techniques. Specifically, Pt and Ag microelectrodes, patterned by hexagonal nanotriangular Ag arrays were prepared, introducing Ag and bimetallic Ag on Pt microelectrode nanostructured systems. Enhancement of surface hydrophilicity was achieved via electric discharge on the electrode surface or via physicochemical interactions (dipping the substrates into NaOH solution). Following removal of the nanospheres, uniform hexagonal arrays of metal nanostructures were revealed and characterized by scanning electron and atomic force microscopy analysis. Parameters relevant to the self-assembly of the colloid arrays and the fabrication methodology employed is discussed with respect to process optimization.