Absorption Spectral Simulation of the End-to-End Linked Gold Nanorods Chain Structure

A classical electrostatic simulation model was developed to study the absorption spectral features of the end-to-end linked and equally-spaced n gold nanorods system with n=2 to 20 for the first time. The model calculation takes into account the dipole-dipole interactions only and solved for the mean polarizability of such nano-chain. We modelled the evolution of the longitudinal surface plasmon (SPlong) absorption band of such system in terms of the interparticle spacings and the number of nanorods. In both cases, either the decrease of interparticle spacing or the increase of n, the evolution of the SPlong bands exhibits a clear spectral red-shift similar to other assembled forms reported in literature. The extent of such spectral shift can be as large as more than 100 nm before levelling off. The interparticle dipole-dipole interaction, characterized by the results in the spectral features of SPlong bands, evidences an effective spatial range of ca. 100 nm.