The book "Surface Plasmon Photonics" by Hongxing Xu offers a comprehensive examination of the optical properties of localized surface plasmon resonances (SPR) in silver and gold nanoparticles in the visible range. It explains how SPR can enable single-molecule sensitivity in surface-enhanced Raman scattering (SERS) under certain conditions. Experimental observations of dimer structures, where two silver particles are connected by a single hemoglobin molecule, demonstrate a simple nanoparticle system capable of enhancing Raman scattering to the point where the vibrational spectra of individual molecules can be recorded. Additionally, the controllable interparticle coupling effects in nanofabricated silver particles on silicon are investigated. The generalized Mie theory (GMT) is employed to analyze the mechanisms of single-molecule SERS and to quantify the optical forces associated with silver nanoparticles. The results indicate that molecules can be trapped by the optical forces induced by SPR excitation, and particle aggregates can be deformed.