Terahertz spectroscopy of l-proline in reverse aqueous micelles

A new method for obtaining room-temperature terahertz (THz) absorption spectra of aqueous-phase biomolecules in the frequency range 1–21 THz (35 cm−1–700 cm−1) is reported. The spectrum for l-proline was acquired by solvating the amino acid within the nanometer-sized interior water pool of reverse micelles dispersed in transparent n-heptane. Terahertz spectra of H2O, D2O and the effect of l-proline concentration and micelle size are discussed, and the results are compared to spectra of solid-phase l-proline and Gaussian calculations.