Silver-Coated Alumina as a New Medium for Surfaced-Enhanced Raman Scattering Analysis

Abstract

A new and simple substrate for inducing surface-enhanced Raman scattering (SERS) was investigated. This new SERS substrate consists of a solid support, such as a microscope slide, coated with alumina and then covered with silver. The alumina used in this work is an agglomerate-free type available in several submicron nominal particle diameters and is widely used as polishing powders. Several substrate conditions, such as the silver thickness used to coat the alumina, the amount of alumina deposited on the glass support, and the particle size of the alumina, were investigated extensively to determine the optimal experimental conditions for obtaining the SERS enhancement. In addition, it was also shown that the SERS enhancement obtained from the silver-coated alumina substrate was comparable to—or even better than—that obtained with previously used substrates. The analytical figures of merit, such as spectral features, signal reproducibility, linear dynamic range, and limits of detection, were investigated to demonstrate the analytical potential of this new substrate.