Surface-enhanced Raman scattering from 1D-3D plasmonic Au nanoparticles: the fourth-power law revisited

According to theoretical estimates, the SERS signal is proportional to the fourth power of the local field, so the maximum intensity should strongly depend on the tuning of the plasmon resonance to the excitation wavelength. However, the experimental data, which are very few, do not confirm the fourth-power law. In this work, the dependence of the SERS enhancement factor on the plasmon resonance tuning for 1D-3D plasmonic nanoparticles is studied for the first time using the gold nanorod, nanotriangle, and nanostar samples obtained by controlled etching and functionalized with Raman molecules. The measured enhancement factors are compared with simulations based on COMSOL and T-matrix method.