Active gold nanoshells for surface enhanced Raman scattering

Abstract

Surface enhanced Raman scattering (SERS) relies on the large localized electric fields near nanoscaled metal surfaces due to the optical excitation of their surface plasmons (SPs) [1]. In metal nanoparticle, the G factor can reach about 1011–1012 when the molecules are trapped at the hotspots [2]. But, the hotspot region in whole nanosystem is very small and hence a low SERS efficiency. The metal nanoparticle incorporating gain media can be called as the active nanoparticle. The gain materials transfer energy to compensate the loss of SP and finally amplify the desired SP response. Recently, Li et al. [3] have introduced the gain media into the core of cubic gold nanoboxs and obtained an extremely high SERS G factor on 1016–1017.