Block-copolymer-based Au/Ag nanoring arrays with widely tunable surface plasmon resonance

We demonstrate a simple route for fabricating Au/Ag nanoring arrays with widely tunable surface plasmon resonce using PS-b-P2VP copolymer templates. Ring-shaped Au dotted arrays are prepared by incorporating Au precursors into the PS-b-P2VP templates. Subsequently, electroless Au plating process enables us to make continuous Au nanoring structures, in which localized surface plasmon spectra cover the range from visible to near-IR regions. Finally, when the Au nanoring arrays are combined with silver-mirror reaction, Au/Ag bimetallic nanoring structures which can also tune the surface plasmon band are successfully fabricated on a wafer scale.