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.

Experimental Analysis of Tear Fluid and Its Processing for the Diagnosis of Multiple Sclerosis

“…Well-defined bands in the spectra correspond to vibrations of the phenylalanine ring (620, 1002, and 1616 cm −1 ), tryp- The most intense bands in the spectra are primarily associated with the vibrations of amide bonds and functional groups of aromatic amino acids. Well-defined bands in the spectra correspond to vibrations of the phenylalanine ring (620, 1002, and 1616 cm −1 ), tryptophan ring (757, 877, 1125, doublet 1336/1358, and 1554 cm −1 ), tyrosine ring (641, doublet 829/853, 1155, 1172, and 1616 cm −1 ), and amide group (1242, 1263, and 1666 cm −1 ) [25][26][27]. The positions of the amide bands reflect the secondary structure of the protein.…”

Applications of Photonics in Agriculture Sector: A Review

“…Raman spectroscopy (RS), similar to IR spectroscopy, is another form of vibrational spectroscopy technique. RS obtains the spectral information of samples due to the occurrence of Raman effects [30]. Prior to understanding the Raman effects, one should look into the light scattering schemes that occur when incident photons interact with molecules in the sample.…”

“…The change in molecule polarizability results in increased Raman intensity, ultimately forming the Raman spectrum when plotted across the investigated wavenumbers. However, this effect is weak as the probability of energy exchange is low [30].…”

“…The existence of fluorescence from impurities may disrupt the results obtained as well. These limitations aside, the RS technique can be combined with IR spectroscopy to deliver satisfactory results as summarized in Table 3 [30].…”

“…A popular excitation light source is the laser which generates powerful monochromatic rays. Not least, UV fluorescent lamp, narrowband LED, high-pressure arc lamp (xeon arc lamp) and low-pressure vapor lamp (mercury vapor lamp) add to the family of excitation light sources [30,31].…”