Trace Analysis and Differentiation of Uranyl Ion Complexes Utilizing Surface-Enhanced Vibrational Spectroscopy

The goal of this project is to detect and differentiate various uranyl ion complexes that can arise from a variety of different uranyl compounds so that uranyl ion detection, speciation, and differentiation can be determined in environmental samples obtained from DOE nuclear waste repositories. Surface-enhanced vibrational spectroscopy (SEVS), which includes surface-enhanced Raman scattering (SERS) and surface-enhanced infrared absorption spectroscopy (SEIRA), is being used to detect and differentiate trace amounts of uranyl ion complexes present both in solution as well as in dry, cast films. Preferentially aligned nanorod arrays produced by oblique angle vapor deposition are being used as the SEVS substrates. Substrate optimization of these nanorod SEVS substrates, which have been shown to exhibit intense SERS and SEIRA responses, is being performed so that these substrates will have improved sensitivity to the uranyl ion, as well as increased stability over time and when exposed to various chemical environments (i.e., solvents, pH, etc.).

Currently funded by the U. S. Dept. of Energy in cooperation with the Westinghouse Savannah River Company through the Savannah River National Laboratory.