In this paper, the temperature characteristics of aliphatic L-asparagine and aromatic L-tyrosine amino acids at low temperature were measured by terahertz time domain spectroscopy. The low frequency (0.1-2 THz) absorption peaks of these two amino acids at room temperature were verified by Fourier transform infrared spectroscopy and Raman spectra. The results show that the terahertz spectra of aliphatic and aromatic amino acids have different responses to temperature. With the decrease in temperature, the absorption peaks of the two amino acids shifted blue, and new absorption peaks appeared in some amino acids. However, the change in absorption peak width is slightly different. In this paper, the vibrational modes of L-asparagine and L-tyrosine are calculated by density functional theory. It is concluded that the vibrational modes of L-asparagine and L-tyrosine are formed by intermolecular forces. (C) 2021 Optical Society of America
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