Yi-Wei Wen, Bo Su, Jia-Hui Wang, Guo-Yang Wang, Ya-Xiong Wu, Jing-Suo He, Cun-Lin Zhang,
https://www.spiedigitallibrary.org/journals/Optical-Engineering/volume-59/issue-5/055107/Terahertz-spectral-analysis-of-different-electrolytes/10.1117/1.OE.59.5.055107.short
Terahertz (THz) technology has become popular worldwide as a
new approach to detecting biomolecules because the vibrational and rotational
energy levels of many biomolecules fall in the THz band and because the THz
wave has the characteristics of low electronic energy, which will not damage
the samples to be measured. Many biomolecules need to maintain their biological
activity in liquid environment. However, as a polar molecule, water has a
strong absorption of THz wave, which is mainly because the vibration frequency
of hydrogen bond in aqueous solution is within the THz frequency range.
Therefore, the best solution is to reduce the action distance between the
aqueous solution and THz wave and control it within 100 μm. Microfluidic chips
can meet such requirements. Therefore, the combination of THz technology and
microfluidic technology can study the dynamic characteristics of biomolecules
in an aqueous solution. The microfluidic chip was fabricated using ZEONOR
1420Rs. The THz transmittance of the material can exceed 95%. The depth of the
microchannel in the microfluidic chip is 50 μm. In addition, the chip has the
characteristics of good airtightness, portability, convenient disassembling,
and reusability. Seventeen kinds of electrolytes were tested with the chip. The
results show that the THz spectral intensity of electrolyte composed of
different anions and cations, so the spectral characteristics of other
electrolyte solutions can be obtained according to the spectral information of
these detected ions.
