Fabrication of TiO2 and Metal Nanoparticle-Microelectrode Arrays by Photolithography and Site-Selective Photocatalytic Deposition

This paper demonstrates a novel and facile technique for the production of microelectrode arrays based on either TiO2 or metal nanoparticles, which combines photolithography and photocatalytic deposition. A procedure that involves photolithographic selective decomposition of superhydrophobic n-octadecyltriethoxysilane (ODS) has been developed to create superhydrophobic/superhydrophilic TiO2 patterns (i.e., microelectrode arrays based on TiO2 nanoparticles). The generated TiO2 patterns can function as molecular microtemplates, in which elevated metal nanoparticle-based microelectrode arrays are produced by photocatalytic deposition to form microelectrode arrays based on metal nanoparticles. Microscopy and atomic force microscopy have demonstrated that the metal nanoparticles grow site-selectively inside the TiO2 microtemplates. This developed approach can be used to create microelectrode arrays composed by either TiO2 nanoparticles or various metal nanoparticles, such as gold, silver, and platinum, with different patterns. The electrochemical behavior of the as-prepared microelectrode arrays has also been characterized by cyclic voltammetry.