Platinum films with controlled 3-dimensional nanoscopic morphologies and their effects on surface enhanced Raman scattering.

The synthesis of Pt thin films with a controlled nanoscopic architecture that can support surface enhanced Raman scattering (SERS) is reported. The syntheses are achieved by replicating the pores of a type of mesoporous silica thin film whose pore structure could be described as a regular array of vertical channels of approximately 9 nm in diameter and their interconnections, forming a 3-dimensional pore network. Electrochemical deposition into the pores followed by the removal of the templates produced Pt films composed of arrays of vertically standing Pt nanorods with narrow gaps between them. The 3-dimensional nanostructure increases the surface area and enables the Pt film to absorb visible light. SERS studies of rhodamine 6G and benzenethiol on such Pt films as substrates reveals that the control of the nanostructure is critical for the SERS effect.