Probing trace lactose from aqueous solutions by terahertz time-domain spectroscopy

Terahertz (THz) waves have unique advantages in detecting biological substances. However, due to the strong ab-sorption of THz waves by water, the development of THz detection technology in this field is seriously restricted. At present, although there are a few methods to detect hydrated materials, they cannot be widely used because of their defects. In this paper, a convenient and promising method for the detection of THz spectra of hydrated substances is proposed. A horn shaped tapered parallel plate waveguide is designed, which can enhance the electrical field of the incident THz wave at its central position, so as to obtain the THz spectral information of hydrated substances in a THz time-domain spectroscopy system. The detection of alpha-lactose dilute solution was demonstrated, the spectral range is from 0.1 to 1.5 THz and the sensitivity can reach the order of femtomole. This method has potential application prospect in the in situ detection of trace hydrated substances, cells and biomolecules. (c) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study introduces a new method for detecting the THz spectra of hydrated substances, which uses a specially designed waveguide to enhance THz waves and achieve the detection of hydrated substances in a THz time-domain spectroscopy system. The successful detection of alpha-lactose dilute solution was demonstrated in the experiment, showcasing the potential application prospects of this method in the future.