School of Materials Science and Engineering, College of Science, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China.
Dalton Trans. 2019 Feb 19;48(8):2569-2573. doi: 10.1039/c9dt00006b.
Highly selective detection of trace metal ions has become one of the most urgent issues in public security and living systems. Developing a highly efficient fluorescent sensor for manganese(ii) (Mn2+) ions is a huge challenge. Herein, by utilizing the solvent regulation approach, a pair of terbium metal-organic frameworks (UPC-36, [Tb2(btdc)3(DMF)(H2O)4]·DMF and UPC-37, [Tb2(btdc)3(H2O)6]) based on a π-electron-rich ligand (H2btdc = 2,2'-bithiophene-5,5'-dicarboxylic acid) has been chosen as highly efficient sensors for the selective detection of Mn2+ ions. Interestingly, the fluorescence of UPC-36 can be quenched by Mn2+, Cu2+, Al3+, Cr3+ and Fe3+ ions, while UPC-37 can only be quenched by Mn2+ ions. For detecting Mn2+ ions, the limit of detection (LOD) values are calculated to be 0.813 mM and 0.715 mM for UPC-36 and UPC-37 respectively. According to the ICP results, UPC-37 has stronger interactions with Mn2+ ions because of the more regular arrangement of ligands existing in UPC-37, so it exhibits a high sensitivity and selectivity (Ksv = 5.25 × 105 M-1).
痕量金属离子的高选择性检测已成为公共安全和生命体系中最紧迫的问题之一。开发一种用于锰(ii)（Mn2+）离子的高效荧光传感器是一个巨大的挑战。在此，通过利用溶剂调控方法，选择一对基于富π电子配体（H2btdc = 2,2'-联噻吩-5,5'-二羧酸）的铽金属有机骨架（UPC-36，[Tb2(btdc)3(DMF)(H2O)4]·DMF 和 UPC-37，[Tb2(btdc)3(H2O)6]）作为 Mn2+离子高选择性检测的高效传感器。有趣的是，UPC-36 的荧光可以被 Mn2+、Cu2+、Al3+、Cr3+和 Fe3+离子猝灭，而 UPC-37 只能被 Mn2+离子猝灭。对于检测 Mn2+离子，UPC-36 和 UPC-37 的检测限（LOD）值分别计算为 0.813 mM 和 0.715 mM。根据 ICP 结果，由于 UPC-37 中配体的排列更加规则，UPC-37 与 Mn2+离子的相互作用更强，因此表现出高灵敏度和选择性（Ksv = 5.25 × 105 M-1）。
