Enabling Technologies for Point and Remote Sensing of Chemical and Biological Agents Using Surface Enhanced Raman Scattering (SERS) Techniques

摘要

First responders and military personnel are in need of a fast, reliable, and accurate method to identify and quantify defense related hazardous materials. Raman spectroscopy is a form of vibrational spectroscopy that is rapidly becoming a valuable tool for homeland defense applications, as it is well suited to the molecular identification of a variety of compounds, including explosives, and chemical and biological hazards. To measure trace levels of these types of materials, surface enhanced Raman scattering (SERS), a specialized form of Raman scattering, can be employed. The SERS enhancements are produced on, or in close proximity to, a nanoscale roughened metal surface, and are normally associated with increased local electromagnetic field strengths. Due to the nature of the SERS substrate fabrication process, there are challenges in substrate reproducibility that often result in the presence of field 'hot spots,' making reliable sample quantification difficult. Using both a portable Raman system and an industry stand-alone, we have investigated commercially available and fabricated SERS substrates with a variety of samples (e.g., standard chemicals, explosives and bacterial endospores), and will report figures of merit for the analysis of substrates and system performance.