Surface-Enhanced Raman Scattering Substrate

Raman spectroscopy has proven to be a reliable field deployable detection technique for assessing chemical threats, including chemical warfare agents, energetic materials, and illicit narcotics. Military and Homeland Security agencies commonly utilize various portable Raman systems in sensitive site exploitation, checkpoint scenarios, and to determine hazardous content on surfaces or containers. Enhanced Raman techniques, such as surface-enhanced Raman scattering (SERS) have been demonstrated to be a vibrant field of research that is growing significantly in scope and applicability while pushing at the ultimate limits of sensitivity. SERS occurs when nanometallic substrates locally amplify electromagnetic fields at or near particle surfaces providing enhancements over 'normal' Raman spectroscopy, typically over a million-fold. Along with other advantages such as reduction of interfering fluorescence, decreased detection times, and reduction of laser power required for analysis, SERS has been positioned to be an ideal technique for low-level, low-consumable detection schemes, while aiming towards miniaturization of instrumentation. The problem to date, however, is the lack of commercially available robust SERS active substrates that have an inherent low background signature which ultimately interferes with obtaining clean SERS spectra from low-level concentrations of threat analytes, while still having at least 104 SERS enhancement. Klarite substrates with nanometer scale patterning of a silicon surface coated with gold had very low background signature and produced repeatable results. However, the Klarite substrates were very expensive and are no longer commercially available. To address the critical need, Lynntech is proposing to develop SERS substrates with nanostructured metal (gold or silver) with low background signature and with at least 104 SERS enhancement using a low-cost scalable process. The SERS substrate will be individually packaged to enable safe storage across broad range of environments.