Tunable multi-wavelength resonance-Raman detection of bacteria and chemicals in complex environments

We are developing tunable-multi-wavelength resonance-Raman spectroscopy and algorithms to enable rapid detection and identification of bacteria and chemicals in complex environments. The system, dubbed SWOrRD, is capable of illuminating a sample containing many chemicals or biological agents with a sequence of laser wavelengths between 210nm and 2000nm; a range which encompasses the resonant frequencies of cells, microorganisms, cellular metabolites, and many chemicals; and measures the resonance-Raman spectra of light scattered from the sample at each laser wavelength. These multiple spectra, which contain much more information about the bond structure that is contained in a single spectrum, are analyzed by a linear-mixture algorithm, based on NRL's ORASIS, to determine the chemical and bacteriological constituents of the sample. The current status of the research will be described.