Stimulated Low-Frequency Raman Scattering in Albumin

Abstract

Stimulated low-frequency Raman scattering (SLFRS) can provide important information on elastic properties of different nanoparticle systems, in particular, biological nanostructures. In the present study, for the first time we investigate low-frequency vibrational modes in human and bovine serum albumin (HSA and BSA), in view of the SLFRS method. We use 20 ns ruby-laser pulses for excitation. The SLFRS frequency shifts, corresponding to acoustic eigenfrequencies of the sample, are registered by Fabry–Pérot interferometers. For HAS, the set of eigenfrequencies obtained is 6 GHz (0.2 cm⁻¹), 10 GHz (0.33 cm⁻¹), and 15.6 GHz (0.52 cm⁻¹), while for BSA, it is 8.7 GHz (0.29 cm⁻¹) and 16.5 GHz (0.55 cm⁻¹). We also measure the conversion efficiency and threshold. The SLFRS can be applied for biological-object identification and impact on the biological objects.