Label free chemical sensors based on plasmonic nanostructures: Modeling and functional characterization

In this work a fast, cheap and reproducible strategy for the realization of gold nanoparticles (NPs) over large areas is presented and their unique optical properties due to the excitation of Localized Surface Plasmon Resonances (LSPR) investigated. Based on thermal de-wetting of thin metal films, this fabrication method allows the realization of waferscale homogeneous distributions of gold nano-islands on planar substrates, providing an interesting alternative to sequential and very expensive manufacture techniques. Furthermore, a numerical method for the description of the optical and functional properties of the proposed metal nanostructures is proposed. Single and multiple gold nanostructures distributed on planar substrates are studied by exploring their possible application as label-free chemical sensors. The proposed analytical method is applied in particular for the study of possible interactions between plasmonic NPs and resonant organo-metallic molecules deposited in form of thin films on the metal nanostructures. The key factors determining the performances of this hybrid plasmonic material as chemical sensor are investigated.