Prof. Toshihiko Kiwa – A terahertz chemical microscope for bio-applications
March 6 @ 4:00 pm - 5:00 pm
Chemical sensing of the water solution with the small amount of volume is important in terms of low-invasive medical diagnosis. In our group, a terahertz chemical microscopy (TCM) based on the laser-excited terahertz technology has been proposed and developed to visualize the distribution of the antibody-antigen bindings on the silicon based sensing plate without any labels on the antibody. The sensing plate can radiate the terahertz pulses by femtosecond laser and the amplitude of the detected terahertz pulses can be related to the chemical or electric potential of the sensing plate surface at where the laser pulses are irradiated. Thus the potential distribution related to the antibody-antigen bindings can be visualized as the map of the terahertz pulses amplitude. Because the sensing area can be limited to the irradiation area of femtosecond laser, a small amount of sample solution is required for this technique. In this presentation, chemical sensing and imaging of the solution samples as well as pH sensing of small amount of water droplet is demonstrated. Also, as one of our recent results, a THz time-of-flight measurement of penetration speeds of cosmetic liquids into the skin are introduced.
Toshihiko Kiwa was received the B. E., M. E. and PhD degree from Osaka University in 1998, 2000 and 2003, respectively. After that, he worked for 1 year as a JSPS fellow at the Research Center for Superconductor Photonics, Osaka University (Tonouchi Lab.), where he was involved in the development of terahertz and superconductor devices and systems. Currently, he is an associate professor of Graduate school of natural science and technology, Okayama University. His research interests include chemical sensors, superconductive devices, and terahertz sensing systems.