Assembly of two-dimension LMOF materials with excellent detection of Fe3+ ion in water based on overlap mechanism

The luminescent metal-organic framework (LMOF) materials are highly desirable applied in detection of large variety of analytes by photoluminescence method. Here, two novel isostructural LMOFs, [EuDTTA(DMF)3]NO3 and [TbDTTA(DMF)3]NO3 (EuDTTA and TbDTTA) [H2DTTA ​= ​2,5-di(1H-1,2,4-triazol-1-yl) terephthalic acid], have been successfully obtained. In the structure, binuclear secondary building units (SBUs) interconnected with ligands utilizing carboxylic acid groups extend to 2D layers, and triazole functional groups of the ligands point to the interior of the pore. Based on overlap mechanism, EuDTTA and TbDTTA demonstrated excellent selective and sensitive detection of Fe3+ ion in water. The quenching constants are 3.63 ​× ​104 and 8.39 ​× ​104 ​M−1 and the detection limits are 4.14 ​× ​10−6 and 1.79 ​× ​10−6 ​M. In addition, the LMOFs exhibit good structural stability and recyclability after several fluorescence detection tests. This work provides two new LMOF materials for the research in the field of detecting metal ions.