大分子荧光化学传感器的构建及其对重金属离子的识别与分离研究

It is of importance to detect and separate heavy metal ions. So, there comes to this proposal.This proposal aims to prepare macromolecular membrane based fluorescent chemo-sensors, which can detect, absorb and separate heavy metal ions. Small molecualar fluorescent probes for heavy metal ions will be first synthesized and then introduced to polymer chians to fabricate macromolecular fluorescent chemosensors. The small molecular probes should bear a reactive group which guarantee it be introduced to macromolecules, except for the receptor and fluorophore in conventional fluorescent probes. To achieve the goal, we put forward a hypothesis as follows: only if the necessary stuctrue of a fluorescent probe is remained, namely, the conjugated π bonds and rigid planar structures remained, its fluorescent properties reained when being introduced to macromolecules. By comparing the properties of the macromolecular fluorescent chemosensor with the small molecular probes, the hypothesis could be proved. In addition, the optimal conditions for the preparation of the macromolecular chemosensors will be established..The changes of the color/fluorescence of the on the macromolecular fluorescent chemo-sensors caused by the coodinations of metal ions will be employed to detect heavy metal ions, such as mercury, lead, zinc and cadmium. The sensitivity and detection limit will be measured. The recognition mechanism to the heavy metal ions both by small fluorescent probe and macromolecular fluorescent chemosensor should be clarified. The know-how to improve the detecting and serarating ability to heavy metal ions wiil be explored. So, the theory and methodology to research macromolecular fluorescent chemosensors will be obtained.

快速识别并除去重金属离子对于环境检测及修复具有重要意义。本项目拟首先合成几种小分子荧光探针，然后将其引入聚合物中，从而构建对重金属离子兼具识别及分离功能的大分子荧光传感器。这几种小分子荧光探针在分子结构上除具备传统荧光探针分子所必须的识别基团和荧光基团外，还须具备可引入大分子链中的可键合基团。为此，我们提出“只要保持小分子探针的共轭大π键、刚性平面结构，可键合基团的引入不致破坏其荧光性能”的假说。通过测试小分子荧光探针及大分子传感器的荧光光谱等性能，验证这个假说。探索构建最优大分子传感器的条件。.利用大分子荧光传感器与重金属离子作用后的荧光/颜色的变化，检测重金属离子。测试所构建的大分子荧光传感器检测重金属离子的灵敏度及检出限。阐明小分子探针及大分子传感器识别重金属离子的机理，探讨提高大分子传感器对复杂金属离子体系的识别及分离能力，为大分子膜传感器的应用提供理论和方法。

重金属离子对水体、土壤造成的污染已不容忽视。制备对重金属离子兼具识别及分离功能的新型大分子材料，用于重金属离子的检测及处理十分必要。本研究项目正是在这个背景下提出的。在国家自然科学基金（NSFC41573106）资助下，我们制备了对Hg2+，Pd2+, Zn2+, Fe3+/Fe2+等重金属离子具有识别及吸附分离功能的荧光共轭大分子。这些材料与重金属子作用后，发生荧光/颜色的改变，可作为重金属离子的光化学传感器，检测重金属离子的存在。同时，这些共轭聚合物材料可以高效吸附重金属离子，将其从污染水体中清除，起到分离重金属离子、净化污水的作用。将荧光体单元引入聚合物，而仍能保持其识别重金属离子的能力，是本项目的重点及难点问题。小分子的结构与性能之间关系的是本项目需探索并解决的科学问题。