Enhanced and polarization dependence of surface-enhanced Raman scattering in silver nanoparticle array-nanowire systems

We report a surface-enhanced Raman scattering (SERS) platform composed of a single Ag nanowire (NW) and nanoparticle array (NW-array). There are three different fundamental combination patterns of NW-array systems. Optical excitation of sandwich nanostructure provides a stronger SERS hot array at the gap between the NW and array. We also have studied the polarization dependence of SERS in the coupled NW-array system for three kinds of pattern. We find SERS are strongly enhanced when the incident light is polarized across the junction between the particle of array and NW, the enhancement is amazingly insensitive to the detailed geometrical structure of coupled pattern.