Study of adsorption behavior of aminothiophenols on gold nanorods using surface-enhanced Raman spectroscopy

Abstract

A comparative study of the adsorption behavior of 4, 3, and 2 aminothiophenol on gold nanorod (AuNRs) solution and film substrates is carried out using surface-enhanced Raman spectroscopy (SERS) to provide information about the adsorption mechanisms of aminothiophenols on AuNRs. SERS from gold nanorods in solution form could reveal the distribution of aminothiophenol molecules adsorbed on different facets of gold nanorods. Significant and sudden changes in the relative intensities of some of the vibrational bands are observed above a particular concentration of aminothiophenol, which could be related to adsorption of molecules on different facets of nanorods. The enhancement factor is found to be maximum for the excitation wavelength close to the absorption maximum of gold nanorods. Our results are not only useful for the application of nanorods as sensors and in molecular electronics, but also depict the potential of gold nanorods as the effective SERS substrate.