Photochemical Strategies to Activate Far-Red Fluorescence with Green Light

用绿光激活远红荧光的光化学策略

• 批准号: 1954430
• 负责人: Francisco Raymo
• 金额: $ 58万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1954430&HistoricalAwards=false
• 关键词: Photochemical; Strategies; Activate; Far; Red

In this project, funded by the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Professor Francisco Raymo at the University of Miami and Professor Hao Zhang at Northwestern University are developing new photochemistry and fluorescence methods to image intracellular components in live cells. This challenging objective first requires the synthesis of a series of structurally related organic dye molecules, which are designed to undergo photoreactions initiated by green light. Photoreaction breaks off a portion of the molecule, thereby generating a new fluorophore, or light emitting molecule, which emits red light. Careful structure design also permits site-specific labeling of intracellular components. The resulting fluorophores enable the imaging of many sub-cellular components in live cells by using high resolution fluorescence microscopy, with spatial resolution at the nanometer level. One goal of these fundamental studies is the identification of optimal structural designs to convert a non-fluorescent reactant into a fluorescent product under mild illumination with green light, a wavelength that is innocuous to live cells. This project is expected to have an immediate impact on photochemistry and fluorescence imaging. Creation of innovative chemical tools to investigate live-cell structures with unprecedented resolution has broader implications in biology and medicine. These research activities provide an outstanding training opportunity for the participating postdoctoral associate, graduate students and undergraduate students. They develop laboratory expertise in chemical synthesis, spectroscopic analysis and fluorescence imaging as well as learn how to culture and manipulate live cells. In the process, they can refine their communication and presentation skills, while also having the opportunity to supervise high-school and undergraduate students in intensive laboratory experiences. This project reinforces an existing student-exchange program with Miami-Dade College, which provides research experiences for students from groups underrepresented in science.Research activities in this project are aimed at the development of a general sensitization mechanism to induce photochemical reactions with green light, thereby providing access to a diverse collection of photocleavable protecting groups with optimal properties for biological applications. New photochemistry is based on modifications to BODIPY (boron-dipyrromethene)-oxazine dyes, which undergo photocleavage of the oxazine component. Dye structures include design elements for spectral tuning, enhancement of aqueous solubility and site-specific attachment to cells. Photoreactions with green light (500 – 530 nm), a wavelength harmless to biological samples, enable bright far-red light fluorescence imaging by generating a new fluorophore. These fundamental studies contribute structural designs to photoactivate fluorescence, under irradiation conditions compatible with live cells, and simultaneously localize multiple spectrally-distinct fluorophores at the single-molecule level with nanoscale precision using single molecule localization microscopy. The unique combination of structural, photochemical and photophysical properties engineered into the proposed compounds can translate into probes with superior performance over the few photoactivatable synthetic dyes developed so far for sub-diffraction imaging of live cells. Thus, this research project, predominantly aimed at the chemical synthesis and spectroscopic analysis of photoswitchable fluorescent constructs, is expected to have an immediate impact on photochemistry and transformative implications in fluorescence imaging.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在这个项目中，由化学部化学结构、动力学和机制B项目资助，迈阿密大学的Francisco Raymo教授和西北大学的张浩教授正在开发新的光化学和荧光方法来对活细胞中的细胞内成分进行成像。这一具有挑战性的目标首先需要合成一系列结构相关的有机染料分子，从而进行由绿光引发的光反应，光反应会分解分子的一部分，产生新的荧光团，仔细的结构设计还可以对细胞内成分进行位点特异性标记，从而可以使用高分辨率荧光显微镜对活细胞中的许多亚细胞成分进行成像。这些基础研究的一个目标是确定最佳的结构设计，以在绿光的温和照射下将非荧光反应物转化为荧光产物，该项目预计是一种对活细胞无害的波长。对光化学和荧光成像产生直接影响，以前所未有的分辨率研究活细胞结构的创新化学工具对生物学和医学具有更广泛的影响。他们培养化学合成、光谱分析和荧光成像方面的实验室专业知识，并学习如何培养和操作活细胞。在此过程中，他们可以提高自己的沟通和表达能力，同时还有机会监督高水平的研究。学校和本科生获得密集的实验室体验。该项目加强了与迈阿密戴德学院现有的学生交换项目，该项目为来自科学领域代表性不足的群体的学生提供研究经验。该项目的研究活动旨在开发一种通用的敏化机制，以诱导绿光的光化学反应，新的光化学基于对 BODIPY（硼-二吡咯亚甲基）-恶嗪染料的修饰，可提供多种可光裂解的保护基团，这些保护基团具有生物应用的最佳性能。染料结构的光裂解包括光谱调节、水溶性增强和与细胞的特定位点附着的设计元素，绿光（500 – 530 nm）的波长对生物样品无害，可产生明亮的远红光。这些基础研究通过生成新的荧光团来进行光荧光成像，从而在与活细胞兼容的照射条件下实现光激活荧光的结构设计，并同时定位多个光谱不同的区域。使用单分子定位显微镜在单分子水平上以纳米级精度进行荧光团的设计，将结构、光化学和光物理特性独特地组合到所提出的化合物中，可以转化为性能优于迄今为止开发的少数​​可光活化合成染料的探针。因此，该研究项目主要针对光可切换荧光结构的化学合成和光谱分析，预计将对光化学和变革性影响产生直接影响。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Photoactivatable Fluorophores for Bioimaging Applications

用于生物成像应用的光活化荧光团

• DOI: 10.1021/acsaom.3c00025
• 发表时间: 2023
• 期刊: ACS Applied Optical Materials
• 作者: Zhang, Yang;Zheng, Yeting;Tomassini, Andrea;Singh, Ambarish Kumar;Raymo, Françisco M.
• 通讯作者: Raymo, Françisco M.

BODIPYs with Photoactivatable Fluorescence

• DOI: 10.1002/chem.202101628
• 发表时间: 2021-06-24
• 期刊: CHEMISTRY-A EUROPEAN JOURNAL
• 影响因子: 4.3
• 作者: Zhang, Yang;Zheng, Yeting;Raymo, Francisco M.
• 通讯作者: Raymo, Francisco M.