Probing organic adsorbate - metal binding chemistry with Surface Enhanced Raman Spectroscopy
Wednesday, October 26, 10AM – 11:30AM
Alexey Zayak, Associate Specialist, Lawrence Berkeley National Laboratory
Surface Enhanced Raman Spectroscopy (SERS) is known for its dramatic signal enhancement, capable of realizing single molecule measurements. While the mainstream approaches to SERS are limited to the task of enhancing the signal, we currently begin to understand that a quantitative chemical analysis using SERS is feasible, although subject to the understanding of complex surface chemistry with many unknown parameters. Here, we perform a detailed analysis of SERS data taken from an organic molecule "trans-1,2-two(4-pyridyl) ethylene" (BPE). We show, that previously unexplained variations in experimental data for BPE arise from the underlying surface chemistry, dependent on the slow binding kinetics of BPE to gold. The latter effect, led us to a direct method of measuring the "chemical enhancement", obtaining a quantitative agreement with theoretical data. We demonstrate that accessing the chemical information simultaneously experimentally and theoretically opens exciting possibilities for using SERS in chemical analysis.
Hosted by Jim Chelikowsky