Local field enhancement dependence on nanoparticle's geometry in Au/TiO<inf>2</inf>/Ti/Si SERS-active substrate for biochemical sensors

Abstract

In this work, we study the effect of surface roughness and shape of Au nanoparticles on the local field enhancement of SERS-active substrates. Our 3D FDTD simulation predicts that the substrate with roughened surface exhibits large field enhancement, especially for cubic shape of nanoparticle. The field enhancement of spherical and cubic nanoparticles is enlarged by Au/Ag alloy and Au nanocage structure which is useful for biochemical sensing applications.