Tunable plasmonic coupling between silver nano-cubes and silver nano-hole arrays

A quasi-three-dimensional (quasi-3D) system composed of Ag nano-cubes and Ag nano-hole arrays was fabricated through a low cost chemical process. The coupling of localized surface plasmons (LSPs) in the cube-hole array system has been investigated through surface-enhanced Raman scattering (SERS) from Rhodamine 6G (R6G) molecules. A SERS enhancement factor as large as 1.1 x 10(8) can be achieved due to this plasmonic coupling effect, and is highly sensitive to geometrical parameters, such as cube-hole array distance, hole diameter, inter-hole spacing and Ag film thickness.