Raman Spectroscopy in Analysis of Biomolecules

Abstract

Raman spectroscopy (RS) is a vibrational spectroscopy technique based on the phenomenon of inelastic light scattering from matter (the Raman effect). It is a versatile tool for probing of biological events at the molecular level and for identification of biomolecules. The characteristic mark of modern RS is the variety of techniques used to explore the Raman effect. In this article the advantages and limitations of different methodologies including conventional Raman, resonance Raman (RR), ultraviolet resonance Raman (UVRR), surface‐enhanced Raman (SER), surface‐enhanced resonance Raman (SERR), Fourier transform Raman (FT‐Raman), micro‐Raman, time‐resolved Raman, and coherent anti‐Stokes Raman scattering (CARS) spectroscopies that can be used for analysis of structure and function of biomolecules are discussed. RR and UVRR spectroscopies are particularly important in biological applications since chromophoric groups (active centers in proteins, aromatic amino acid residues, and nucleotides), which in many cases are responsible for the function of biomolecules, can be probed selectively, by tuning the excitation wavelength to the electronic absorption transition of the chromophore. Surface‐enhanced techniques (SER and SERR) are the most sensitive, allowing RS of single biomolecules. The interpretation of the Raman spectra of biomolecules requires identification of spectra‐structure correlations. Numerous marker bands for conformation, hydrogen bonding, protonation, and hydrophobic interaction of the main constituents of biopolymers are provided and discussed.