Chemical and biological processes studied with advanced imaging techniques

我们的研究项目集中在开发基于荧光的方法来研究化学和生物系统，以及应用这些方法获得的基础知识来产生新的材料和诊断。我们能够合成具有理想化学反应性和光物理行为的定制荧光探针，然后开发和利用最先进的单分子荧光成像方法，在我们追求复杂系统的机制基础。我们研究工作的基础是我们监测单个分子活动的能力。单分子光谱学领域已经从最初关注生物物理现象的研究发展到对非均质介质中反应的机理探索，包括表面反应和各种纳米复合材料/催化剂的反应。最诱人的是最近在生物系统成像和催化剂表征方面的突破，具有“超分辨率”（超过衍射极限）和灵敏度。这些技术利用化学反应（荧光化合物）的荧光诱导/增强来可视化，绘制并最终理解在微观和纳米（十亿分之一米）水平上发生的事情。然而，这些技术大多局限于光化学触发的荧光探针子集（它们是物理观众-信标）。在仔细设计对感兴趣的反应性化学物质（活跃参与者“化学耀斑”）作出反应的荧光化合物时，存在着巨大的机会来询问生物系统和纳米材料。在即将到来的拨款期内，我们将利用我们过去6年的进展以及超分辨率成像领域的最新发展，研究3个相互关联的当代问题。(1)我们将设计和制备荧光探针来监测脂质膜的氧化还原状态，以及荧光亲电探针来触发与脂质过氧化副产物类似的反应。我们的目标是建立活性氧（ROS）的化学和它们的生物学之间的关系。（II）我们将利用我们新开发的探针，结合SMS和超分辨率成像策略，对生物系统和纳米材料中的关键氧化还原过程进行可视化、制图和研究。（III）我们将开发新的SMS策略来探索超分子结构和组装动力学/纳米材料的高产量和高质量材料的调谐条件。在这种情况下，我们的目标是获得关键的机械信息，并在适用的情况下将其转化为制造更好的纳米材料。总的来说，我们将获得关于新化合物的光化学/光物理的知识。我们将开发具有许多研究人员寻求的功能的分子。化学选择探针和成像方法将使与ROS产生相关的细胞功能和活性的广泛影响的根本性转化发现成为可能。探针和成像方法也将为制备改进的纳米材料/超分子结构铺平道路。新的成像技术将成为纳米科学质量和结构表征的标准。我们的计划将提供具有里程碑意义的例子，探索独特的方法，开发尖端的成像技术，以理解化学和生物系统。

Our research program centres on the development of fluorescence-based methodologies to study chemical and biological systems, and on the application of the fundamental knowledge gained using these methods to generate novel materials and diagnostics. We are able to synthesize customized fluorescent probes with desirable chemical reactivity and photophysical behaviour, and to then develop and exploit state-of-the-art single molecule fluorescence imaging methodologies with them, in our pursuit of the mechanistic underpinning of complex systems. Fundamental to our research work is our ability to monitor single molecules in action. The field of single molecule spectroscopy has evolved from its original focus on the study of biophysical phenomena, to mechanistic exploration of reactions in heterogeneous media, both on the surface and within a diverse range of nanocomposite materials/catalysts. Most tantalizing are recent breakthroughs in the imaging of biological systems and characterization of catalysts at work with “super resolution” (beyond diffraction limit) and sensitivity. These techniques exploit the induction/enhancement of fluorescence upon a chemical reaction (fluorogenic compounds) to visualize, map and ultimately understand what occurs at the microscopic and nanoscopic (a billionth of a meter) level. The techniques are however mostly limited to a subset of fluorogenic probes that are photochemically triggered (they are physical spectators - beacons). Tremendous opportunities exist to interrogate biological systems and nanomaterials upon careful design of fluorogenic compounds that respond to reactive chemical species of interest (active players “chemical flares”).In the coming grant period we will capitalize on our progress of the past 6 years and on recent developments in the field of super resolution imaging working on 3 interrelated contemporary problems. (I) We will design and prepare fluorogenic probes to monitor the redox status of lipid membranes and also fluorogenic electrophilic probes to trigger reactions akin to those observed with by-products of lipid peroxidation. Our goal is to establish the relationship between the chemistry of reactive oxygen species (ROS) and their biology. (II) We will visualize, map and study key redox processes both in biological systems and nanomaterials implementing our newly developed probes, combining SMS and incorporating super resolution imaging strategies. (III) We will develop new SMS strategies to explore the structure and the assembly dynamics of supramolecular structures/nanomaterials tuning conditions for high yields and improved quality materials. Our goal in this case is to gain key mechanistic information and translate it to the manufacture of better nanomaterials when applicable.In general, we will gain knowledge on the photochemistry/photophysics of new compounds. We will develop molecules that have functions that many researchers seek. The chemoselective probes and imaging methodologies will enable fundamental transforming discoveries of broad impact on cell function and activity correlated with ROS production. The probes and imaging methods will also pave the way to prepare improved nanomaterials/supramolecular structures. New imaging technologies to be developed will become the standards of quality and structural characterization in nanoscience. Our program will provide landmark examples where unique approaches are explored and cutting-edge imaging technologies are developed toward understanding chemical and biological systems.