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

Article type: Research Article

Authors: Qi, Ji | Motwani, Pratik | Zeng, Jianbo | Wolfe, John C. | Shih, Wei-Chuan^{; ;}

Affiliations: Department of Electrical & Computer Engineering, University of Houston, Houston, TX, USA | Department of Biomedical Engineering, University of Houston, Houston, TX, USA

Note: [] Corresponding author. E-mail: wshih@uh.edu

Abstract: 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.

Keywords: Plasmonic nanostructures, surface-enhanced Raman scattering (SERS), Raman spectroscopy and microscopy, vibrational spectroscopy

DOI: 10.3233/BSI-140100

Journal: Biomedical Spectroscopy and Imaging, vol. 4, no. 1, pp. 95-103, 2015