Anisotropic Metal Nanoparticles for Surface-Enhanced Raman Scattering

Resum

This chapter reviews recent research on the use of the most common anisotropic gold and silver nanoparticles (NPs) morphologies toward Surface-Enhanced Raman Spectroscopy (SERS). It focuses on the intrinsic shape-dependent SERS performance of anisotropic NPs, highlighting comparative and systematic SERS studies on NPs, mainly in solution. The chapter gives a basic theoretical introduction to the optical properties of NPs and the SERS effect, as well as the relevant experimental techniques included in this report. It presents the most common anisotropic NP shapes, namely nanorods, nanotriangles, nanocubes and nanostars. The chapter is dedicated to more complex structures that can offer additional advantages. After a short introduction of each shape class, it briefly describe the optical properties, and discusses some recent works where the morphology-dependent SERS performance can be appreciated. The unusual optical properties of metal NPs are related to the presence of strong plasmon resonances in the visible and near-IR (NIR) ranges of the electromagnetic spectrum.