荧光探针双子表面活性剂的制备及胶束成像研究

The ability to obtain a molecular-level understanding of the chemistry that takes place at liquid/solid and liquid/liquid interfaces, especially self-assemble behavior of amphiphilic molecules, is key to the development and improvement of interfacial chemistry. However, the study of surface science is hampered by the difficulty to get micelle imaging with high quality by traditional techniques. Recently Job H. J. Thijssen presented first confocal-microscopy study of synergistic effects in emulsions stabilized by both colloidal particles and a common fluorescent dye that acts as a surfactant. In practical applications, the self-assemble of amphiphilic molecules has changed because of the invasion of the large fluorescent probe. In this project, we design a series of Gemini surfactants with conjugated oligomers as spacer groups to avoid the influence of organic fluorophore on the surface activity of the base surfactant. Confocal-fluorescent microscopy will be employed for micelle imaging to discover the initial and real behavior of amphiphilic molecules. Gemini surfactants with different ions with multitopologies will be synthesised and their photophysic properties will also be characterized under different circumstance. This in situ microscopic imaging may enable us to have a better insight formation of different micelle morphologies with transition between them. Therefore the combination of fluorescent probe and Gemini surfactant presents us a new tool to provide convincing data of self-assemble behavior of amphiphilic molecules.

两亲分子在液-液、固-液界面自组装行为的过程研究对于界面化学的发展至关重要，但传统成像技术无法对胶束的自组装过程进行高质量的成像。最新研究（2011）表明两亲性分子搭载荧光探针可以利用共聚焦荧光显微镜对胶束成像。然而，有机荧光素的入侵式搭载影响了表面活性剂本身的性质，从而无法真实的反映两亲分子自组装行为的过程。本项目以共轭寡聚物链为双子表面活性剂的联接链，作为两亲分子有效组成部分，消除现在胶束成像荧光探针的天然缺陷，通过共聚焦显微镜荧光成像系统，揭示两亲分子自组装形为的过程及机理。为此，本课题通过制备系列不同拓扑结构、不同离子性质的荧光探针双子表面活性剂分子，研究不同物理及化学环境下荧光探针的光物理性质，实现不同形貌的胶束的共聚焦荧光显微镜成像，以图像的方式呈现胶束形成的机制及不同形貌的胶束间相互转变的过程，为界面化学的研究提供可视化平台。

两亲分子的聚集行为研究对于界面化学的研究至关重要，其聚集形态的研究主要依赖于冷冻透射电子显微镜，这在很大程度了限制了相关的研究。光谱法研究两亲分子的聚集具有灵敏方便的特点，通过共聚集荧光显微镜便可利用含有荧光基团的两亲性分子的光谱属性，对两亲性分子聚集形态进行成像研究。为了减少荧光链段对两亲分子聚集的影响，该项目将共轭的刚性链段设计成为双子表面活性剂的连接链，制备了以阳离子、两性离子以及非离子链段为侧链的刚柔嵌段寡聚物。利用光谱法研究了荧光双子表面活性剂的聚集行为，利用其水溶性和生物相容性，探索了制备的材料在生物医疗中的应用。研究发现制备的荧光嵌段寡聚物兼具光热以及光动力效果，可以很好的抑制肿瘤的生长，同时具有很低的生物毒性以及肾代谢能力，是一种优异的光治疗有机纳米材料。