Direct observation of multiple reaction pathway and transition state ensembles in molecular systems having large degree of freedom by single molecule measurements

2021 Fiscal Year Final Research Report

• Project/Area Number: 17KT0009
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Multi-year Fund
• Section: 特設分野
• Research Field: Transition State Control
• Research Institution: Osaka City University
• Principal Investigator: Sakota Kenji 大阪市立大学, 大学院理学研究科, 准教授 (80346767)
• Project Period (FY): 2017-07-18 – 2022-03-31
• Keywords: 微小液滴 / タンパク質 / イオントラップ

Outline of Final Research Achievements

The following studies were conducted to measure fluorescence from proteins dissolved in microdroplets with high sensitivity. (1) The electrode for droplet trapping used in the previous studies cannot increase the solid angle of light collection, which makes it difficult to measure fluorescence with high sensitivity. The fluorescence emitted from microdroplets was measured 80 times more sensitively by using the end-cap trap we have developed in this study. (2) We observed the fluorescence enhancement effect caused by the confinement of the excitation light irradiated on the droplet inside the droplet. The sensitivity was improved by about three orders of magnitude compared with the conventional method, together with the improvement of the sensitivity of fluorescence detection by the improvement of the ion trap.

Free Research Field

光物理化学

Academic Significance and Societal Importance of the Research Achievements

蛍光検出は，測定対象を「その場」で「非破壊的に」観測できる有力な手段である．本研究では，光共振器として振る舞う単一微小液滴を上手く利用することにより，蛍光検出感度の更なる向上を達成した．この方法をタンパク質のような大自由度分子系に適用することによって，これまで感度不足のために計測することができなかった分子系の振る舞いを明らかにすることが可能となり，大自由度分子系が示す複雑なダイナミクスを分子レベルで理解するための基礎データを取得することが可能となる．