A Novel Multifunctional Eu (III)-MOF Luminescence Sensor for Detecting NB, Fe3+, and Cr2O72- With Outstanding Sensitivities and Selectivities

The bowl-shaped flexible carboxylic acid zwitterion 1,1 ',1 ''-(2,4,6-trimethylbenzene-1,3,5-triyl)tris (methylene)-tris(4-carboxy-pyridinium)tribromide (H3LBr3) ligand-based lanthanide metal-organic framework (Ln-MOF) was synthesized for the first time under solvothermal conditions. Single crystal X-ray diffraction analysis indicates that the molecular formula of Ln-MOF is [EuL2(H2O)4Br3]<middle dot>2H2O (1). Luminescence sensing experiments demonstrate that 1 shows obvious fluorescence quenching for nitrobenzene (NB), Fe3+, and Cr2O72- with low detection limits of 0.118 mu M, 9.098 nM, and 17.409 nM, respectively. 1 can be regarded as a luminescence sensor with multiple functions, displaying high selectivity, wonderful antiinterference ability, outstanding sensitivity, and recyclability to detect NB, Fe3+, and Cr2O72-.