Nanoshell, nanosphere, and nanowire geometries for hot spot formation in surface enhanced Raman scattering

Silver nanoshells, nanospheres and metal coated dielectric nanowires have been directly compared for their surface enhanced Raman (SERS) activity. SERS was measured from trace deposits of Rhodamine 6G (Rh6G). It was found that the SERS enhancement is largest for samples that are 3D in nature compared to 2D arrays. Furthermore Ag coated dielectric nanowires had the strongest SERS. These results demonstrate the importance of electric field hot spots and molecular orientation in the SERS process.