January 21, 2009
FRONTIERS IN MATERIALS SCIENCE
VINSE COLLOQUIUM SERIES
Dr. Kevin Hewitt
"Imaging Cancerous Cells Overexpressing EGFR using Surface Enhanced Raman Spectroscopy (SERS)"
Abstract. Nearly one of two individuals will experience some form of cancer in their lifetime. Methods which detect the early stages of cancer are critical to reducing mortality rates. In particular, a number of cancers are characterized by overexpression of the Epidermal Growth Factor receptor (EGFR)- a membrane protein which mediates cell growth, proliferation and differentiation in multiple tissues. Many epithelial tumors have been found to express high numbers of EGF receptors, and receptor levels are associated with poor clinical prognosis in cancers of the bladder, breast and lung. Antibodies for EGFR tagged with fluorescent probes have been used as contrast agents with limited success. To overcome the small contrast, we propose to use surface enhanced Raman spectroscopy. Conventional Raman spectroscopy is a weak light scattering process which provides molecular specific information. By coupling the light to a nanoparticle assembly an overall enhancement of 7-8 orders of magnitude is possible; this is referred to as the surface enhanced Raman scattering (SERS) effect. Recent experiments have used this idea by targeting EGFR overexpressing cells with “Raman reporter molecule” embedded SERS particles to detect binding in-vivo. We use a more basic approach to target EGFR overexpressing cells and have found promising results.