Surface-sensitive vibrational spectroscopic techniques rely on molecular interactions with relevant interfaces. For instance, surface-enhanced Raman scattering (SERS) requires that molecules interact with the metal surface at short distances of 2 nm or less without disrupting the surface atoms. In this presentation, anisotropic nanostructures such as gold nanostars will be used in conjunction with SERS to detect trace molecules. Two challenges and approaches to better predict structure-function behavior of noble metal nanoparticles will be discussed. A combination of experimental measurements that provide molecular-level insight coupled with semi-empirical modeling will be shown to improve the systematic use of gold nanostars by providing a method for predicting the stability and hence, the fate of nanomaterials in various environmental conditions. After these considerations, localized surface plasmon resonance (LSPR) spectroscopy and SERS will be exploited for the direct, qualitative and quantitative detection of small biologically relevant molecules. In the future, these results could be expanded for different nanomaterial shapes, compositions, and molecular targets.
Amanda Haes (University of Iowa)