Morphological, plasmonic and SERS characterization of DC-sputtered gold nanoislands

Chemical mapping of molecules adsorbed on plasmonic nanostructures is a powerful technique for biomolecular sensing, surface chemistry and plasmon–matter interactions. DC-sputtered gold nanoisland (GNI) substrates have attracted significant attention recently due to its excellent plasmonic enhancement, structural stability and simple fabrication. We provide multimodal characterization of GNI morphological evolution by correlating data obtained from scanning electron microscopy (SEM), localized surface plasmon resonance (LSPR) extinction spectroscopy and surface-enhanced Raman scattering (SERS) microscopy. A rigorous determination of the SERS enhancement factor for benzenethiol self-assembled monolayers on evolving GNI substrates is presented. Rapid statistical analysis shows excellent large-area SERS uniformity by hyperspectral Raman imaging systems based on active-illumination which enables parsimonious sampling of only 2.7% area of the field of view, greatly improving sampling efficiency.