Study of Hydration of Biomolecules and Nanoparticles in Aqueous Solutions and Suspensions Using Coherent Laser Spectroscopy

Abstract

A considerable increase in the concentration of H₂O ortho spin isomers and H₂O₂ molecules in the hydration layer at the interface of water and molecules of DNA, denatured DNA, and protein α- chymotrypsin is found using low-frequency laser spectroscopy of four-photon scattering (FPS). Spectra of rotational resonances of H₂O ortho and para spin isomers in aqueous solutions of various biopolymers and in distilled water are obtained in the range of 0 to 100 cm−1 with a spectral resolution of ≈0.12 cm⁻¹. Numerical analysis of the FPS spectra shows that concentration of H₂O₂ molecules in the DNA hydration layer increases by a factor of three after denaturation. In addition, FPS spectra of aqueous α-chymotrypsin solutions are obtained in the spectral range of ±7 cm⁻¹ at concentrations of 0 to 20mgcm⁻³. It is found out that the speed of hypersound in the aqueous protein solution measured by the shift of the Brillouin components in the scattering spectrum increases and cubically depends on the concentration.