| Project/Area Number |
18K03570
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 13040:Biophysics, chemical physics and soft matter physics-related
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| Research Institution | Japan Women's University |
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Principal Investigator |
SHIMADA Ryoko 日本女子大学, 理学部, 教授 (90346049)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | プラズモン発熱 / Soret効果 / DNA 分子運動 / DNA / ソレー効果 |
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| Outline of Final Research Achievements |
In this work, we examined conformational changes and the center of mass motion of DNA molecules (microscopic Soret effect) under the large periodic temperature gradient to understand the macroscopic Soret effect of DNA molecules in solution. The Brownian simulation was also carried out.
We have achieved a large periodic temperature gradient (0.5K/μm) through the plasmonic heating from periodic silver domains. Using this large periodic temperature, we have successfully visualized the center of mass motion and conformational changes of DNA molecules in polyethylene glycol solution. The DNA molecules, labeled with fluorescent dyes, were found to concentrate in high-T zones, confirming the positive Soret effect. In addition, for DNA molecules, stretched conformations bridging two hot zones were occasionally observed and their diffusion appeared to deviate from the simple Fickean behavior from our simulation, possibly because of the microscopic Soret effect within the molecule.
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| Academic Significance and Societal Importance of the Research Achievements |
(1)周期的金属ドメインの表面プラズモン効果により発生する熱を周期的微小熱源として利用したこと：これまでは単一の金属微粒子をレーザー光で励起することで得られる単調減衰型の温度場のみが実現されていた。本研究では周期的金属ドメインにより、微小空間に巨大な周期的温度勾配を実現した。(2)巨大温度勾配下におけるDNA分子の局所的形態変化と空間移動を明らかにしたこと：巨視的なSoret効果とDNA分子の内部状態(自由エネルギー)の変化を対応づけ、巨視的Soret効果の分子機構の理解に寄与した。
以上、高分子系におけるSoret効果の分子機構を解明する上で貴重な知見をもたらし、その物理化学的意義は大きい。
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