Quantitative detection of THz-ATR spectra of aqueous samples under strong-field terahertz wave

Owing to the characteristics of THz wave, the terahertz time-domain spectral (THz-TDS) system has potentials in the field of biological macromolecule detection. However, water with strong absorption effect on THz wave exists in most biological detection, so the research focus in this field is to study aqueous samples. In view of these, THz spectroscopy system has research value for qualitative and quantitative detection of alpha-lactose and its water-containing samples. This research used a THz-TDS system with LiNbO3 crystal to generate strong THz wave that was used to test 0.29 mmol alpha-lactose samples with water content of 15 mL-930 mL by using attenuating total reflection (ATR) prism. The absorption peak at 0.53 THz is detected, and with the increase of water content, the curve of absorption spectrum is observed to move up on the whole. This research has a guiding role for the test and improvement of water content limit in this field.

Automated summary

Due to the characteristics of THz wave, the terahertz time-domain spectral (THz-TDS) system has potential in the detection of biological macromolecules. The focus of research in this field is to study aqueous samples, as water has a strong absorption effect on THz waves. This study used a THz-TDS system with LiNbO3 crystal to generate strong THz waves and tested alpha-lactose samples with different water contents. The absorption peak at 0.53 THz was detected, and the absorption spectrum shifted upwards with increasing water content. This research guides the testing and improvement of water content limits in this field.