Advancing In-liquid AFM for Nanoscale Measurement of Potential Distribution at Biomolecular Surfaces and Interfaces

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14602
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 29020:Thin film/surface and interfacial physical properties-related
• Research Institution: Nagoya University (2023); Kanazawa University (2022)
• Principal Investigator: Hirata Kaito 名古屋大学, 工学研究科, 特任助教 (50909984)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 原子間力顕微鏡 / 液中電位計測 / 生体分子 / 脂質二重層膜

Outline of Final Research Achievements

In this study, we established a method to apply open-loop electric potential microscopy(OL-EPM), which is enable to measure local surface potential in liquid, to biomolecular measurements for the first time. Specifically, we developed the conducitve substrate for the potential measurement and the cantilever, which serves as the detector for OL-EPM. These components were applied to a supported lipid bilayer with positively and negatively charged heads. The results showed a potential distribution reflecting the head charges, indicating that this technique has the ability to measure the potential distribution of biomolecules. In the future, the foundational technology developed in this study can serve as a basis for the potential measurement of various biomolecules.

Free Research Field

ナノ計測工学

Academic Significance and Societal Importance of the Research Achievements

近年では生命現象への原子間力顕微鏡（AFM）の進展が目覚ましい。しかし、表面電荷・電位を局所計測できる技術は確立されておらず、生体分子機能において液中イオンや生体分子の表面電荷が関係する現象の理解が進んでいない。本研究で確立してきた基盤技術により生体分子の「電荷・電位」計測を可能にすることで、従来技術では困難であったイオンチャネルによるイオン輸送や膜分解ペプチドの静電的相互作用による脂質分子の吸着・脱離など、生体分子/溶液界面の電位分布が関係するとされる生体分子機能のナノレベルでの機序解明に貢献する。それらは、創薬・医学の学術的な理解に必要であり、生命科学分野の発展に繋がることが期待される。