DARPA awards research team $1.2M grant to study surface enhanced Raman ...( CAMBRIDGE Mass. July 17 2008 -- The ...)

CAMBRIDGE, Mass., July 17, 2008 -- The Defense Advanced Research Projects Agency (DARPA) has awarded a $1.2 million grant to an interdisciplinary team of Harvard University researchers to study surface enhanced Raman scattering (SERS) for the first phase of a potential three-year effort.

If all phases of the development program are completed, researchers could receive up a total of up to $2.9 million in funding.

Ken Crozier, Assistant Professor of Electrical Engineering at the School of Engineering and Applied Sciences (SEAS) will serve as the principal investigator for the grant. His co-investigators include Eric Mazur, Balkanski Professor of Physics and Applied Physics at SEAS and the Department of Physics and Aln Aspuru-Guzik, Assistant Professor of Chemistry and Chemical Biology at the Department of Chemistry and Chemical Biology.

SERS relies upon a fundamental phenomenon in physics called the Raman effectthe change in the frequency of monochromatic light (such as a laser) when it passes through a substance. Properly harnessed, Raman scattering can identify specific molecules by detecting their characteristic spectral fingerprints. Potential applications of SERS include the sensing and identification of a range of materials, including chemical and biological agents, improvised explosive devices, and toxic industrial waste.

"While SERS offers enormous potential for chemical detection and sensing, its practical use has been hampered by the need for improved knowledge of the fundamentals of the enhancement mechanisms," says Crozier.

It turns out that Raman scattering cross sections are very small, about 1012-1014 times smaller than fluorescence cross sections. In the 1970's scientists discovered that by placing molecules on roughened metal surfaces they could achieve significantly larger Raman signals, enabling the detection of molecules. Nevertheless the gain has not been enough to make SERS readily usable in detec
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