Biological Sensing with Terahertz Circular Dichroism Spectroscopy
Final rept. 1 Jun-31 May 2005
CALIFORNIA UNIV SANTA BARBARA
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We have developed a circular dichroism spectrometer working in the terahertz THz frequency regime. As THz spectroscopy is specific to collective vibrational modes in macromolecules and collective modes in condensed, polar media such as water, the spectrometer should provide spectral fingerprints of biological materials. Moreover, by focusing on circular dichroism the spectrometer should provide fingerprints of these materials uncontaminated by the strong background absorbance of water and other polar materials. We have built this spectrometer and have pushed its signal to noise down to 1 part in 104. While this is more than sufficient to detect the strong circular dichroism of macroscopic, chiral objects, it is apparently insufficient to observe circular dichroism arising from common biological materials. Current efforts are aimed at 1-2 orders of magnitude improvements on this detection limit.
- Chemical, Biological and Radiological Warfare
- Atomic and Molecular Physics and Spectroscopy