Plasmon Coupling Between Gold Nanorod and Adsorbed Organic Molecule

Abstract

In this article, the dipolar response of gold nanorods on the adsorbed organic molecule, benzonitrile, has been investigated. We estimate the average aspect ratio of nanorods using TEM measurements. The longitudinal and transverse plasmon modes of nanorods are measured and analyzed using theoretical estimates. Well characterized gold nanorods are further used to establish the effect of plasmon coupling on the characteristics of the ligand molecule. Making use of the dipolar response function model we are able to match the experimental and theoretical values of the frequencies of vibrational modes of ad-molecules upon adsorption on the rod surface. We believe that our studies using optical probes can explain the effect of the metallic nanorod, as a whole, on the ad molecules and can thereby serve as a sensitive tool to understand metal-ligand interactions for such metallic nanostructures.