The size effect of silver nanocubes on gap-mode surface enhanced Raman scattering substrate

摘要

This study demonstrates the size effect of silver nanocubes with the namely dimension 50 and 70 nm atop the massed silver surface (denoted, 50-NcIM and 70-NcIM) on surface enhanced Raman scattering (SERS) by using rhodamine 6 G and melamine with the irradiation of 532, 633, and 780 nm lasers. In addition, the NcIM substrate was exhibited a strong SERS effect under 633 and 780 nm laser irradiation. The enhancement factors of 50-NcIM and 70-NcIM samples were reached nearly 109 and 108, respectively. The simulation results show that plasmonic cavities (PC) derived from 50-NcIM and 70-NcIM respectively possess the stronger electromagnetic field density and the larger extended PC area under 633 and 780 nm laser irradiation, interpreting the experimental results well. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.