Trial to measure IR absorption spectrum of the biomolecule in the water

2014 Fiscal Year Final Research Report

• Project/Area Number: 24655006
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Physical chemistry
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: SAKAI Makoto 東京工業大学, 資源化学研究所, 准教授 (60298172)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 水溶液 / 赤外分光 / 生体分子 / 超解像 / ローダミン６G

Outline of Final Research Achievements

Water intensely absorbs IR light. Therefore, IR light can penetrate only up to a few tens of micrometers and it is impossible to observe the IR absorption spectrum of solute molecules in the water by traditional IR spectroscopy. In this project, we applied a new detection system based on the TFD-IR microscopic technique. In this case, the visible and IR lasers are focused by an objective reflection lens and the transient fluorescence from the solute molecule in the water is collected by the same objective. Only the transient fluorescence near the focal point of the objective is observed, and we can monitor the IR absorption process of solute molecules located near the surface where a sufficient amount of IR light can penetrate even in the strongly IR absorbing solution. Using this system, we succeeded in monitoring TFD-IR signal of rhodamine 6G molecules in the water, and observing the TFD-IR spectrum that is corresponding to IR absorption spectrum in the 1100-1800 cm-1 region.

Free Research Field

物理化学