Photonic nose" for chemo- and bio-agent detection: a novel surface enhanced Raman approach"

Surface enhanced Raman Scattering (SERS) has great potential as a tool chemical and biological detection. First, ultra-sensitivity is provided by remarkable Raman enhancement factors (>10^14); even delving into the ultimate limit for any sensor, singlemolecule detection. Second, since Raman scattering does not require a fluorescent analyte, SERS offers great generality in the range of detectable target molecules. Third, high-resolution Raman spectroscopic fingerprints provide excellent specificity,i.e., the ability to uniquely identify and discriminate amongst numerous target and non-target contaminant molecules (for larger bio-molecules Raman tags can be incorporated into highly specific receptor molecules). In order to capitalize on thispotential, however, one requires a synthesis technique and manufacturing protocol for reliable, reproducible and quantitative SERS-active detection sites, all in a form factor suitable for integration with other sensor elements. The primary focus of thephase I effort will be to assess the applicability of new photo-generated SERS-active synthesis techniques for sensor applications. Additionally, potential designs for a phase II detection system will be constructed and assessed. Ultra-sensitive chemicaland biological detection would provide enabling performance improvements in numerous and varied applications. Examples range from environmental monitoring, to detection of chemical and biological weapons, to unearthing of land-mines and unexplodedordnances, to medical breath analysis, and to industrial monitoring of leaks in subterranean pipes or storage tanks (only trace quantities of leaked chemicals migrate to the surface for detection). The inherent importance of these applications, which areonly a few of many, illustrates the magnitude of potential benefits resulting from the advancement of ultra-sensitive chemical detection technology.