Biological Applications of Raman Spectroscopy

Abstract

Vibrational spectroscopic studies of biomolecular polymers have demonstrated a number of advantages over other spectroscopic methods, including minimal or no damage to the sample and ease of sampling arrangements. Spectral sensitivity to a range of parameters that affect biomolecular structures is an added advantage for studies of environmental change, in particular, tissue degradation resulting from changes in pH, temperature, degree of hydration, or bacterial or drug attack. Prior to the advent of Fourier transform (FT) Raman spectroscopy using nearinfrared excitation, classical Raman spectroscopic studies of molecules and mate­ rials of biological interest were fraught with difficulties arising principally from the generation of fluorescence by visible radiation and the real possibility of sam­ ple degradation from the use of the relatively high laser powers necessary for sample illumination. Hence, the major advantages of Raman spectroscopy over infrared spectroscopy, namely, the weak Raman scattering of water and of glass cells, could not be exploited fully. For the particular studies reported here, the power and potential of the Raman spectroscopic technique for the analysis of biological tissues is now realized.