ABSTRACT
Terahertz (THz) technology has emerged as a novel biomedical method for diagnosing cancer and studying the dynamics of biomaterials (Fitzgerald et al. 2006; Kawase et al. 2003; Oh et al. 2007, 2009, 2011; Pickwell and Wallace 2006; Woodward et al. 2003). In order to further investigate biomedical sciences and technologies, studies need to be conducted on the dynamics of biological molecules, such as DNA, proteins, and lipids (Son 2009). Most biological molecules can only function in biological environments. erefore, an understanding of biological environments is essential to develop biomedical technologies based on biological sciences. Liquids, which include water, are major components that determine the biological environment. e interaction between liquids and biological molecules can indicate the biological molecular dynamics (MD) information based on the biological environment. e intra-and intermolecular dynamics in biological molecules are caused by hydrogen bonding between water and biological molecules or between water molecules themselves. e typical timescale of the hydrogen bonding network of water at room temperature is in the picosecond range, which corresponds to a few THz (~1012 Hz) in frequency. e bulk dielectric relaxation and oscillatory motion of liquids occur in the THz frequency range, which is positioned between the microwave and far-infrared frequency ranges. is frequency range can also be used as a bridge to connect the spectral results of the microwave and infrared regions. For several decades, THz spectroscopy has been used to explain the dielectric relaxation, hydrogen bonding network, and ultrafast dynamics of liquids including water and molecular, polar, and nonpolar liquids.
