ABSTRACT
Terahertz (THz) radiation is generally considered to be safe and noninvasive for biomedical applications due to its low photon energy as compared to gamma-and x-rays. e resonant coupling of electromagnetic radiation with biomolecules has been of interest since the early theoretical predictions by Fröhlich that biological systems exhibit longitudinal electric modes (Foster et al. 1987; Fröhlich 1975; Gabriel et al. 1987). is possibility of resonant coupling has had an impact on the regulations of microwave radiation exposure (Kuster et al. 2004; Maier et al. 2000; Repacholi 2001). Past studies have indicated that when biomolecules like nucleosides and carbohydrates are irradiated with mid-and long-infrared (IR) radiation from a free-electron laser for time ranges of 30-120 min, they undergo structural changes (Dlott and Fayer 1991; Yang et al. 2005, 2007). e structural changes are dependent on time as well as frequency of irradiation and can be detected using Fourier transform infrared (FTIR) spectroscopy. Biomolecules like proteins and amino acids also exhibit vibrational modes in the far-IR or THz region of the electromagnetic spectrum (Markelz et al. 2000; Plusquellic et al. 2007).
