Terahertz absorption characteristics of strong acid solution based on microfluidic chip

Abstract

The rotational mode and vibrational mode of many biomolecules are all located in terahertz band, and the photon energy of terahertz wave is low, which is only millivolt level, and will not damage the internal structure of molecules, so terahertz time-domain spectroscopy technology has a good application prospect in biological detection. In addition, most biomolecules can only exert their biological activity under liquid conditions, so it is necessary to study the interaction between biomolecules in liquid environment. In the study of the interaction between biomolecules and terahertz wave in solution, minimizing the absorption of terahertz waves by water molecules has become a research hotspot in recent years. The microfluidic chip reduces the absorption of terahertz waves by reducing the distance between the measured sample and the terahertz waves, and has important application value in the detection of biological samples. By changing the concentration of hydrogen ions in the aqueous solution, different pH values can be obtained. In this paper, Zeonor 1420rs, which has high transmission rate to terahertz wave, is selected as the material of microfluidic chip, and the microchannel depth is 50 μm. Then we combine terahertz technology and microfluidic technology, and prepare three kinds of strong acid solutions with different pH values. By analyzing the terahertz time-domain and frequency-domain spectra of strong acid solutions, we can explore the influence of different pH solutions on terahertz wave absorption, and provide necessary reference for the application of terahertz technology in the field of biochemistry.