Regular Hexagonal Gold Nanoprisms Fabricated by a Physical Method: Toward Use as Ultrasensitive Surface‐Enhanced Raman Scattering Substrates

Abstract

A simple physical approach to prepare gold (Au) nanoparticles with sharp edges for increasing surface‐enhanced Raman scattering (SERS) response is presented. The shape evolution process of Au nanoparticles under different fabrication conditions is studied, and a thermodynamic model is adopted to explain the shape transition. Single‐crystalline Au nanoprisms with regular hexagonal shape can be formed at a certain annealing temperature. Coating of these Au nanoprisms with graphene causes them to exhibit a SERS enhancement of 60x. This is the first demonstration of a physical approach to fabricate regular hexagonal Au nanoprisms that exhibit an ultrasensitive SERS effect. Furthermore, the local field distribution of a series of Au nanoprisms with different sizes is simulated to better understand their ultrasensitive SERS performance.