TiO2 Thin Layer Coated Ag Nanoarrays Complex for Surface-enhanced Raman Scattering Substrate

A novel method to prepare TiO2-coated Ag nanowire arrays for use as surface enhanced Raman scattering (SERS) active substrate is studied. First, Ag nanowires with an average diameter of 60 run and length of several mu m were synthesized in an anodic aluminum oxide (AAO) template by direct electrodeposition into the template. Then TiO2 thin layers with a 20 nm thickness were coated on Ag nanoarrays in large scale by a hydrolysis approach of tetrabutyl titanate. The SERS substrates prepared by this strategy have been proved as excellent candidates for the detection of organic pollutants by enhancing the SERS signals of these target species. The detection limit of methyl-parathion (MP) can be reduced to 10(-6) M.