Surface-enhanced Raman scattering of size-selected polyynes (C8H2) adsorbed on silver colloidal nanoparticles

► SERS studies of size-selected C8H2 adsorbed on Ag colloidal particles. ► Concentration dependence of SERS intensities correlates well with that of absorption spectrum, suggesting the electromagnetic mechanism of SERS. ► Positions of SERS bands are different for different SERS enhancers, i.e., Ag colloids and Ag island film.