Ionic screening of nanoparticles for maximum surface enhanced Raman scattering

PHYS 489

Tyson O. Friday, tyson-friday@uiowa.edu and Amanda J. Haes. Department of Chemistry, University of Iowa, Iowa City, IA 52242
SERS is a plasmonic phenomenon whereby specific molecules undergo a dramatic increase in the intensity of the observed inelastically scattered light. The magnitude of SERS vibrational bands depends on the electromagnetic properties of the nanostructured surface and on the chemical (electrostatic and charge transfer) states that exist between the analyte and the nanostructured surface. In this poster, we systematically vary ion concentration and composition as well as solution pH for various analytes. Correlated SERS, extinction spectroscopy, and zeta potential data reveal interesting trends in the observed enhancement of the SER signal.