Supramolecular-based Fluorescent Sensors and Surfactants

超分子化学，或“分子外的化学”，涉及由两个或更多分子组成的结构，这些分子通过弱吸引力而不是化学键结合在一起。超分子体系的一个简单例子是主客体包合物，其中客体分子被包含在更大的笼状有机主体分子的空腔中(就像桶中的球)。最常见的宿主分子家族是环糊精(CDS)，这是一种葡萄糖的环状形式，在水中呈桶状，并在其内腔内强烈结合客体分子。在我所在的研究组之前基于荧光研究主客体包合体系基本性质的成功基础上，这一提议支持的变革性研究涉及此类超分子体系在两个重要领域的新应用：1)分子传感和2)用于分子传递的超分子表面活性剂和胶束。分子传感涉及特定目标分子的检测和测量，例如有机环境污染物；提出了三个这样的项目。首先，将进行合理的化学修饰CD的设计，以获得具有靶向结合特性的宿主，作为感兴趣的特定客体的传感器。其次，将探索在非水溶液中增强荧光信号的潜力，以扩大超分子传感器的使用范围，使其超越水溶液。这部分研究将包括对目前在非水介质中发生的主客体包结现象研究不足的基础调查。第三，将探索两种形状独特的荧光主机作为荧光传感器的潜在应用。在分子递送中，特定的感兴趣的分子，如药物，被包裹或附着在分子系统上，运输到感兴趣的区域，如肿瘤，然后释放以作用于靶区。提出了一种特定的分子给药方案，涉及超分子主客体表面活性剂的设计和合成，超分子主客体表面活性剂可以形成胶束或囊泡，这种大的细胞状分子结构可以结合药物分子，并且可以被触发破坏药物在靶点的释放。因此，该项目涉及基础研究和有针对性的应用研究的平衡结合。**

Supramolecular chemistry, or "chemistry beyond the molecule", involves structures consisting of two or more molecules held together by weak forces of attraction as opposed to chemical bonds. A simple example of a supramolecular system is a host-guest inclusion complex, in which a guest molecule becomes included within the cavity of a larger, cage-like organic host molecule (like a ball in a bucket). The most common family of host molecules are the cyclodextrins (CDs), cyclic forms of glucose sugar that take on a bucket-like shape in water, and strongly bind guest molecules inside their internal cavities. Building upon the previous success in my research group involving fluorescence-based investigations of the fundamental properties of host-guest inclusion systems, the transformative research to be supported by this proposal involves the novel application of such supramolecular systems in two important areas: 1) molecular sensing and 2) supramolecular surfactants and micelles for molecular delivery. Molecular sensing involves the detection and measurement of specific target molecules, such as organic environmental pollutants; three such projects are proposed. First, the rational design of chemically modified CDs will be undertaken to obtain hosts with targeted binding properties, to serve as sensors for specific guests of interest. Second, the potential for fluorescent signal enhancement in non-aqueous solutions will be explored, to extend the use of supramolecular-based sensors beyond water solutions. This part of the study will include fundamental investigations into the currently understudied phenomena of host-guest inclusion occurring in non-aqueous media. Third, the potential application of two fluorescent, uniquely-shaped hosts as fluorescent sensors will be explored. In molecular delivery, a specific molecule of interest, such as a drug, is encapsulated or attached to a molecular system, transported to the area of interest, such as a tumor, and released to act upon the target area. A specific molecular delivery project is proposed, involving the design and synthesis of supramolecular host-guest surfactants, which can form micelles or vesicles, large cell-like molecular structures which can incorporate drug molecules, and which can be triggered to disrupt to release the drug at a target site. Thus this project involves a balanced combination of fundamental and targeted, applied research.**