Impulsive stimulated Brillouin spectroscopy for assessing viscoelastic properties of biologically relevant aqueous solutions

Brillouin spectroscopy has recently emerged as a valuable tool for assessing microscopic viscoelastic properties in biological tissues and cells. For many practical biomedical applications, the viscoelastic measurement techniques should be sensitive to low sample concentrations in biological media. In this report, we assess the sensitivity of a recently improved impulsive stimulated Brillouin scattering (ISBS) setup. We explored biologically relevant solutions in distilled water using citric acid, glycine, and sucrose, for which we performed Brillouin measurements. We detailed the peak fitting methodology and analyzed the Brillouin shift and linewidth as a function of concentration. We discuss the sensitivity of the ISBS setup to low concentration measurements and its implications to biological applications.