Assembly Of Near-IR Fluorescent Nanostructures With Emergent Properties

凭借有机和高分子化学计划的这一奖项，布拉德利史密斯教授计划在他最近发现的方酸-轮烷作为非常明亮和非常稳定的荧光近红外（NIR）染料的基础上再接再厉。下一代的自组装方法将被开发，以产生方酸大环包合物的定量产量。该方法将用于构建具有涌现特性的精细近红外荧光纳米结构。也就是说，组装的纳米结构的物理性质、化学稳定性和分子识别性质上级单独的构建块。这种自组装策略的一个有吸引力的特点是它的通用性，这意味着构建块（大环和方酸染料）可以与几乎任何类型的靶向配体结合，以快速产生荧光成像探针，这将在材料科学，生物医学科学和纳米技术中产生广泛的影响。它们将使科学家能够进行以前不可能的光子实验。该项目的一个实际目标是利用方酸-轮烷作为核心支架构建近红外荧光树枝状聚合物，这将有许多应用，特别是在采用荧光共振能量转移（FRET）的生物医学成像和诊断过程中。一个具体的目标是提供新的荧光试剂，使新的方法来研究复杂的过程中的基因传递到细胞使用阳离子树枝状聚合物作为转染剂。另一个实际的目标是生产近红外荧光成像探针，可以成像许多类型的癌细胞;因此，它们将有助于肿瘤生物学的研究，允许在小动物模型中检测癌症，并可能最终促进荧光引导的癌症手术。研究生的核心培训将在超分子光化学，但项目的应用方面将教他们如何将他们的发现转化为实际成果。该提案的最终实际目标是升级“有机结构解析”，这是一本免费的互联网练习册，已经为世界各地数千名化学学生提供服务，其中许多人在设备简陋的学校或欠发达国家。

With this award from the Organic and Macromolecular Chemistry Program, Prof. Bradley Smith plans to build on his recent discovery of squaraine-rotaxanes as very bright and extremely stable fluorescent near-infrared (NIR) dyes. Next-generation self-assembly methods will be developed to produce squaraine-macrocycle inclusion complexes in quantitative yields. The methods will be employed to construct elaborate NIR fluorescent nanostructures that have emergent properties. That is, the photophysical properties, chemical stabilities, and molecular recognition properties of the assembled nanostructures are superior to the individual building blocks. An attractive feature of this self-assembly strategy is its generality, which means that the building blocks (macrocycles and squaraine dyes) can be combined with almost any type of targeting ligand to rapidly produce fluorescent imaging probes that will have broad impact in materials science, biomedical science and nanotechnology. They will enable scientists to conduct photonic experiments that were previously impossible. One practical aim of the project is to utilize squaraine-rotaxanes as core scaffolds to construct NIR fluorescent dendrimers, which will have many applications, especially in biomedical imaging and diagnostic processes that employ Fluorescence Resonance Energy Transfer (FRET). A specific goal is to provide novel fluorescent reagents that enable new approaches to studying the complex process of gene delivery into cells using cationic dendrimers as transfection agents. Another practical aim is to produce NIR fluorescent imaging probes that can image many types of cancer cells; thus, they will aid studies of tumor biology, allow cancer detection in small animal models, and perhaps eventually facilitate fluorescence guided cancer surgery. The core training of research students will be in supramolecular photochemistry, but the applied aspects of the projects will teach them how to translate their discoveries into practical outcomes. The final practical aim of the proposal is to upgrade "Organic Structure Elucidation", a free internet workbook that already serves several thousands of chemistry students around the world, many of them in poorly equipped schools or under-developed countries.