Abstract

There are various ions in our body, such as sodium ion and potassium ion. Breaking of ion balances will lead to serious diseases. Therefore, the sensing systems for ions are required in the medical diagnoses. Conventionally, the distribution of ions is measured by the ion chromatography. However, this system can not separate ions that have similar magnitude of polarities. Our group developed a detection system named THz Chemical Microscope (TCM), which can use the amplitude of THz wave to visualize the chemical potential changes in the water solution. A device named the sensing plate is that the amplitude of radiated THz wave changes if there are chemical reactions on the sensing plate. Ion sensitive membranes are immobilized on the surface of SiO₂ side of THz sensing plate and dropped the ion solution with different concentration, which lead to different amplitude of radiated THz wave. Therefore, ions in solution can be detected by TCM. In this work, we first detected the amplitude of THz wave changes with dropping nano liter level water. From this result, ions can be detected by using several hundred μm size ion sensitive membrane.

© 2015 Japan Society of Applied Physics, Optical Society of America