选择性光化学传感器的制备及其在金属元素的地球化学中的分析新方法研究

This project aims to prepare some optical chomesensors which could not only detect but also separate Hg(Ⅱ), Zn(Ⅱ) and Cd(Ⅱ) metal ions (MIs). In our designed method, probes for MIs will be synthesized at first and then be introduced to the surfaces of silica hollow microspheres to obtain optical chemosensors.The probes in our proposal should bear three functional groups, they are described as follows. The first one is OH/NH2, which can react easily with the groups on the surfaces of silica. The second one is chromophores, which could show the changes of color or fluorescence. The third one is chelating groups, which could capture the metal ions.When the probes are introduced to the previously prepared silica hollow microspheres, the microsphres would be endowed with the capacity of detecting the harmful metal ions such as Hg(Ⅱ) and Cd(Ⅱ).. Due to the high specific surface areas of the silica hollow microspheres, when the optical chemosensors were prepared, these microspheres would have been enhanced the absorption capacities for MIs. Moreover, the silica hollow spheres have channels which linked the external and the internal surfaces of the hollow spheres. Thus, the total areas for the load of probes and the subsequent absorption of MIs increased greatly. Alao, this way could make the functionalized silica microspheres separate MIs.. For the practical apllication in soil and environmental detection, two or more hollow microspheres (optical chemosensors) could be used at the same time. Whether they will show synergy or interference will be studied as well. In addition, flow injection analysis (FIA) will be used with fluorescent and spectrophotometry for the real online detection of MIs in this proposal.. In summary, a novel chemosensor with bifunctional applications both in dectction and separation of heavy metals will be synthesized and used in environmental geochemistry. The as-prepared chemosensors will be employed to investigate the space distribution of harmful metal ions in surface water,settlings and soil. Also, a model of the release, the transform and the conversion of metal ions will be established.

如何简单而高效地识别有害金属离子并将其尽可能的除去对于环境治理及保护具有重要的意义。本项目拟采用一步法，以聚苯乙烯微球为模板制备二氧化硅空心微球，然后将具有识别功能的小分子探针引入到空心微球的表面，赋予其同时具有识别及分离金属离子的功能。制备出集高选择性与分离功能于一体的空心微球光化学传感器。利用这种光化学传感器与目标金属离子作用后的荧光/可见光的变化，来检测金属离子如汞、锌、镉等的存在。通过优化制备条件，表征光化学传感器的结构特征，深入研究光化学传感器识别金属离子的机理，探讨光化学传感器对复杂金属离子样品的抗干扰性，为光化学传感器的应用提供理论和方法。拟结合流动注射分析技术，实现对含有害金属离子实际样品的在线检测，以期获得方便、快捷、高效的有害金属检测方法。详细研究有害金属在地表水、沉积物和土壤中的空间分布特征并建立有害金属在不同介质体中及其之间释放、迁移和转化模式。

该项目执行至今，按照原定研究计划，我们合成了一种萘酰亚胺基荧光探针小分子，并将其引入聚苯乙烯微球表面，从而制备了对汞离子具有识别及分离功能的光化学传感器。该光化学传感器与汞离子作用后颜色及荧光均发生改变，可选择性识别汞离子。这种聚合物微球基光化学传感器与汞离子作用后可被EDTA解吸，可以多次重复使用。使用10次后，仍然显示较好的识别及吸附汞离子的能力。从而建立了一种可用于地球化学中的重金属离子分析新方法。. 此外，我们还合成了一种钌配合物基探针分子，并成功地将其引入聚氨酯膜表面，从而制得了一种可用于汞离子识别及分离能力的聚合物膜材料。该聚合物膜与汞离子作用后可迅速产生颜色变化。同时，不同浓度的汞离子溶液与聚合物膜作用后，得到不同的颜色。据此，我们制作了聚氨酯基汞离子检测“试纸”，用于汞离子浓度的快速检测。这种汞离子检测膜可以用于含有汞离子的废水处理，处理后，水中的汞离子浓度大大降低，显示了极好的去除汞污染的能力。. 我们正在合成一种罗丹明基荧光探针分子，希望将其引入多孔聚合物膜的表面，从而制备能识别及除去重金属离子的材料，用于环境检测及重金属分离，可望用于水体及土壤重金属污染的防治。. 在本项目资助下，已有两篇研究论文在国际期刊发表，另有两篇研究工作已投稿，待发表。详见研究成果部分。