Silver nanostructures: From individual dots to coupled strips for the tailoring of SERS excitation wavelength from near-UV to near-IR

In this paper, we report the preparation of silver nanostructures with plasmon absorption peaks tuned by the metal arrangement. Silver nanostructures were prepared by sputtering onto a patterned polymer surface. A surface polymer grating was achieved by modification with an excimer laser. Depending on the amount of deposited silver, randomly distributed silver dots or coupled silver wires were obtained. The plasmon absorption shifted from 500 to 800 nm for a configuration of random dots to that of coupled wires, respectively. Prepared samples were used as substrates for surface enhanced Raman scattering (SERS) excited by near-UV and near-IR wavelengths. The absorption peak position and SERS response strongly depended on the silver arrangement.