Periodic metal resonator chains for surface enhanced Raman scattering (SERS).

A periodic arrangement of chains of gold disks shows pronounced plasmonic grating resonances. These have a clear impact on the surface enhanced Raman-scattering (SERS) signal from 4-methylbenzenethiol molecules, which form self-assembled monolayers on the gold surface: Besides a clear polarization dependence, the SERS-spectra also exhibit a maximum when the excitation laser wavelength matches the plasmonic grating resonance. These features are explained by a combined near and far field coupling of the individual plasmonic dipoles allowing the design of optimized nanostructures for effective SERS substrates in the future. [ABSTRACT FROM AUTHOR]