太赫兹时域光谱技术是一种新兴的无损探测技术。利用太赫兹波的低能性以及大部分生物分子的振动跃迁和旋转在该频段表现出的强色散和吸收作用等特点, 可以对生物分子及生命体的活动进行无损探测和研究。本文分别采用透射式和反射式太赫兹时域光谱系统, 对不同质量比的褪黑素压片进行测试, 分析它在太赫兹波段的光学性质, 发现它在0.29、0.50、0.70、0.91、1.20、2.17和2.55 THz处存在特征吸收峰; 频域谱的强度随样品浓度的变化呈线性关系。利用Gaussian 09及Gaussian VIEW软件进行模拟分析, 得到褪黑素在0.46、0.91、1.15、2.01、2.23和2.61 THz处存在特征吸收峰, 为实验结果提供了有力地支持。这些工作为褪黑素等生化样品的检测和鉴定提供了依据和参考。

Terahertz time-domain spectroscopy is a new nondestructive detection technique, which uses the property of low power of terahertz wave, and the characteristics of strong dispersion and absorption of the vibrational transitions and rotations of most biomolecules are shown in this frequency band. These make it possible,to have nondestructive detection and the study of biological activities. In this work, transmission and reflection of terahertz time-domain systems were respectively used to carry out testing melatonin tablets with different mass ratio, and analysis of its spectral properties in terahertz band were also given. It could be concluded that it had characteristic absorption peak at 0.29, 0.50, 0.70, 0.91, 1.20, 2.17 and 2.55 THz. The intensity of the frequency spectrum has a linear relation with the concentration of the sample. In addition, Gaussian 09 and Gaussian VIEW software were used to perform simulation, and the characteristic absorption peaks of melatonin in 0.46, 0.91, 1.15, 2.01, 2.23 and 2.61 THz were acquired, which provided a strong support for experiment results. All these works are the basis and reference for the detection and identification of biochemical samples such as melatonin.