具有螯合效应的MOF荧光传感器的合成及其检测微量金属离子的研究

The detection of trace metal ions by MOF (Metal-Organic Frameworks) fluorescent sensor is a popular research topic in recent years. But the varieties of MOFs need to be increased, the ranges of detected ions need be expanded, the sensitivity and selectivity need to be improved, and the detection mechanism need to be further studied. Based on the chelation mechanism of ion detection, we use new conjugated pyridines, flexible carboxylic acid ligands and metal ions to build MOF fluorescent sensors with chelate effect in this project. It is noteworthy that the detection of trace metal ions was carried out by the chelation interactions between metal ions and the unsaturated coordination sites (oxygen, nitrogen and sulfur) in the cavity. Moreover, the morphology of MOF was regulated by modulator, and the influence of the morphology and particle size was investigated. Finally, the synthesis of conjugated pyridines and MOF was guided by analyzing the detection mechanism. As a result, this project can not only expand the types of the MOF fluorescent sensors for detecting metal ions, but also greatly enhance the sensitivity. In addition, the MOF fluorescent sensors have high development and used value in detecting the trace metal ions in living organisms and drinking water.

金属有机骨架(Metal-Organic Frameworks，简称MOF)荧光传感器检测金属离子是近几年比较热门的研究领域。但是此类MOF的种类较少，能够检测离子的类别有限，灵敏度及选择性有待提高，检测机理需要深入研究。本项目以离子检测的螯合作用机理为导向，首次合成含有巯基、羟基的共轭多吡啶类有机配体，将其与柔性的多齿羧酸配体和金属离子自组装，构筑具有螯合效应的MOF荧光传感器。利用MOF空腔内裸露的不饱和配位点（氧、氮和硫原子）与被检测的金属离子间的螯合作用实现对金属离子的检测。加入调制剂调控MOF的形貌，研究形貌及粒度对离子检测的影响。通过对检测机理的分析，指导配体及MOF的设计合成。本项目最终不仅能拓展MOF荧光传感器检测离子的种类范围，还将大幅度提升灵敏度，使基于MOF荧光传感器的离子检测技术能够在生物体内微量金属离子检测、饮用水质检测等方面具有实际应用价值。

用于检测金属离子的MOF荧光传感器虽有较多报道，但是此类MOF的种类较少，能够检测离子的类别有限，灵敏度及选择性有待提高，检测机理需要深入研究。本项目从三个方面开展工作，取得了较好的成果：（1）二维MOF纳米片荧光传感器方面的研究。首次合成了共轭多吡啶类有机配体，将其与过渡金属离子及柔性羧酸配体自组装，得到二维晶体Zn2(SBA)2(BPTP)，并对其进行形貌调控及超声剥离，得到二维MOF纳米片，其在荧光检测方面具有显著的效果；（2）过渡金属MOF荧光传感器方面的研究。合成的镉金属有机骨架{[Cd(BIPA)(IPA)]·DMF}n和{[Cd(BIPA)(HIPA)]·DMF}n能够选择性识别Hg2+和 Pb2+离子，{[Cd(BIPA)(NIPA)]·2H2O}n能够检测Fe3+和Cu2+离子。合成的锌配位化合物[Zn(OOCC6F5)(H2O)(C12H8N2)2](OOCC6F5) 在28个离子中，能够识别Fe3+，Cu2+，Ni2+ 和 CrO42-；（3）稀土金属MOF荧光传感器方面的研究。稀土配合物Eu2(TDA)4(OOCCH3)2(H2O)2 除了能够检测金属离子，还能选择性识别孔雀石绿和尿酸，具有极低的检测限和高的灵敏度。本项目的开展丰富了MOF荧光传感器的种类及传感范围，具有一定的应用前景。