Pentagon-Shaped Plasmonic Nano-pillars as efficient SERS substrates

A pentagon-shaped plasmonic nanodimer structure has been proposed for obtaining moderately high surface enhanced Raman scattering (SERS) enhancement which can be potentially employed for chemical and biosensing. Here, we investigate the response of plasmonic effect of the pentagon-shaped nanodimers through exhaustive finite difference time domain modelling. The pentagon-shaped nanostructure exhibits high electromagnetic enhancement in the hotspots at the center of the dimer that can be tailored by adjusting the gap between nanostructures, the substrate material, the size of the nanostructures, and the nanostructure material. The maximum SERS enhancement achievable from the proposed substrates is of the order of ~10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup>. The electromagnetic field distribution and enhancement factor for the pentagon-shaped nanodimers have been extensively modelled in the wavelength range from 400 nm to 2000 nm.