Fluorescence on -off switching by single wavelength irradiation: Development of highly durable nanoparticles and application to single particle fluorescence measurement

• Project/Area Number: 21K18934
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 32:Physical chemistry, functional solid state chemistry, and related fields
• Research Institution: Osaka University
• Principal Investigator: Miyasaka Hiroshi 大阪大学, 大学院基礎工学研究科, 教授 (40182000)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2022: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000); Fiscal Year 2021: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
• Keywords: 超解像蛍光観測 / 蛍光スイッチング / 会合体生成 / ナノ粒子 / １波長制御 / 超解像 / 蛍光ブリンキング / 単一ナノ粒子 / 単一波長スイッチ

Outline of Research at the Start

蛍光ON-OFF制御可能な分子を用い、その単一分子蛍光像の重心を数nmの空間分解能で決定する超解像観測法は、ナノメートルサイズの構造やダイナミクスの直接的知見取得を可能としている。しかし、この手法は蛍光像の大きさに依存するゲスト分子濃度や光退色の制約から、取得できる知見はごく狭い空間（数μm四方程度）や時間（数分）に限られてきた。本研究では、最近、申請者らが見出した可視一波長照射下で粒子全体として蛍光が明滅（ON-OFF）する有機ナノ集合体を対象に、この蛍光明滅の機構解明、蛍光ON-OFFスイッチング制御手法の開発と確立を行い、測定可能時間・空間の飛躍的拡大を目的とする。

Outline of Final Research Achievements

It was found that nanoparticles composed of more than 10000 molecules enabling the controlled fluorescence ON-OFF states exhibit fluorescence ON-OFF behaviors as a whole particle. Because these nanoparticles allows the fluorescence measurement with weak excitation light intensity due to an increase in the light absorption probability, they enable long-time measurement when they are applied to the super-resolution fluorescence microscopy. In this study, detailed measurements and analyses were carried out with the aim of elucidating this ON-OFF mechanism. As a result, when ON-state molecules are produced adjacent to each other by a photoreaction, a significantly weakly fluorescent aggregate is formed, which captures excitation energy, leading to the fluorescent OFF state of the whole particle. On the other hand, the fluorescence of the whole particle was turned on when the ring-opening reaction took place in the aggregates resulting in the independent ON state.

Academic Significance and Societal Importance of the Research Achievements

単一分子の蛍光像の重心を数nmの分解能で決定し超解像を得る手法は、静的画像のみならず単一分子の動的拡散挙動測定も可能とする。この方法では蛍光ONとOFF状態をスイッチできる分子が重要な役割を果たす。しかし測定には非常に強い励起光強度が必用で、色素の光劣化も迅速に進行するため、長時間、広空間域の知見を得ることは困難であった。本研究では、近年我々が見出した可視単一波長照射下で、全体として蛍光ON－OFF挙動を示すナノ粒子を対象に、その構解明を行った。得られた知見から、非常に弱い照射光強度で測定可能かつ長時間測定を可能とする新たな蛍光ON-OFF可能なナノ粒子の合理的設計が可能となった。

Research Products

• [Int'l Joint Research] Lille University(フランス)
• [Journal Article] Spatial distribution of single guest molecules along thickness of thin films of poly(2-hydroxyethyl acrylate) (2022)
  • Author(s): Ito Syoji、Hiratsuka Kengo、Takei Satoshi、Nishi Hiroyasu、Kitagawa Daichi、Kobatake Seiya、Miyasaka Hiroshi
  • Journal Title: Photochemical & Photobiological Sciences Volume: 21 Issue: 2 Pages: 175-184
  • DOI: 10.1007/s43630-021-00147-2
  • Peer Reviewed / Open Access
• [Journal Article] Visualization of the microstructure and the position-dependent diffusion coefficient in a blended polymer solid using photo-activation localization microscopy combined with single-molecule tracking based on one-color fluorescence-switching of diarylethene (2022)
  • Author(s): Ito Syoji、Funaoka Misato、Hanasaki Itsuo、Takei Satoshi、Morimoto Masakazu、Irie Masahiro、Miyasaka Hiroshi
  • Journal Title: Polymer Chemistry Volume: 13 Issue: 6 Pages: 736-740
  • DOI: 10.1039/d1py01100f
  • Peer Reviewed
• [Journal Article] Edge-to-Center Propagation of Photochemical Reaction during Single-Crystal-to-Single-Crystal Photomechanical Transformation of 2,5-Distyrylpyrazine Crystals (2022)
  • Author(s): Kohei Morimoto, Daichi Kitagawa, Hikaru Sotome, Syoji Ito, Hiroshi Miyasaka, Seiya Kobatake
  • Journal Title: Angew. Chem. Int. Ed. Volume: 61 Issue: 52
  • DOI: 10.1002/anie.202212290
  • Peer Reviewed
• [Presentation] ペリレンジイミド誘導体の単一ナノ粒子発光挙動 (2023)
  • Author(s): 射手矢 つきみ, 蔭山 浩崇, Ali Eftekhari, Aude Bouchet, Michel Sliwa, 濱谷 将太, 北川 大地, 小畠 誠也, 五月女 光, 伊都 将司, 宮坂 博
  • Organizer: 日本化学会 第103春季年会
• [Presentation] 共役分子固体の単一ナノ粒子発光特性：置換基およびサイズ依存性 (2022)
  • Author(s): 射手矢 つきみ, 蔭山 浩崇, 伊都 将司, 五月女 光, 宮坂 博
  • Organizer: 日本化学会 第102春季年会
• [Presentation] Ultrafast Multiphoton Spectroscopy of Higher Excited States (2022)
  • Author(s): Hiroshi Miyasaka
  • Organizer: 28th IUPAC Symposium on Photochemistry
  • Int'l Joint Research / Invited
• [Presentation] Single-Particle Emission of Perylenediimide Nanoparticles (2022)
  • Author(s): Tsukimi Iteya, Syoji Ito, Hikaru Sotome, Daichi Kitagawa, Seiya Kobatake, Hiroshi Miyasaka
  • Organizer: 28th IUPAC Symposium on Photochemistry
  • Int'l Joint Research
• [Presentation] Super-Resolved Measurement of Excitation Energy Transfer (2022)
  • Author(s): Hirotaka Kageyama, Syoji Ito, Hikaru Sotome, Daichi Kitagawa, Michel Sliwa, Hiroshi Miyasaka
  • Organizer: 28th IUPAC Symposium on Photochemistry
  • Int'l Joint Research
• [Presentation] Photochemical Processes in Higher Excited States Produced by Multiphoton Absorption and Multiple Excitation in the Condensed Phase (2022)
  • Author(s): Hiroshi Miyasaka
  • Organizer: VII Iberian Photochemistry Conference
  • Int'l Joint Research / Invited
• [Presentation] 単一波長可視光照射による蛍光性ジアリールエテンナノ粒子の発光スイッチング (2021)
  • Author(s): ○武井 佑実, 伊都 将司, 五月女 光, 森本 正和, 入江 正浩, 宮坂 博
  • Organizer: 2021光化学討論会
• [Presentation] 蛍光性ジアリールエテン誘導体の一波長蛍光スイッチング特性：励起条件とホストマトリクス依存性 (2021)
  • Author(s): ○相川 みちる, 船岡 美里, 伊都 将司, 森本 正和, 入江 正浩, 宮坂 博
  • Organizer: 2021光化学討論会