Highly Fluorescent Cadmium Based Metal-Organic Frameworks for Rapid Detection of Antibiotic Residues, Fe3+ and Cr2O72- Ions.

Here, two novel 3D Cd(II)-MOFs, [Cd3·L·(BTB)2·2DMF] and [(Cd3O2)·L·BTC] (denoted as CUST-532 and CUST-533, L = 9,10-bis(N-benzimidazolyl)-anthracene, BTB = 1,3,5-tris(4-carboxyphenyl) benzene, BTC = 1,3,5-benzenetricarboxylic acid, CUST = Changchun University of Science and Technology), were synthesized by solvothermal conditions. Both CUST-532 and CUST-533 are 3D (3,8)-c topological nets with the same point symbol of {43}2{46·618·84}. PXRD and TGA analyses prove that CUST-532 and CUST-533 have good structural stability and thermal stability. On the basis of the high fluorescence characteristics, the results of fluorescence sensing experiments show that CUST-532 and CUST-533 can be used as multifunctional chemical sensors to achieve rapid fluorescence quenching response to antibiotic residues, Fe3+ and Cr2O72- ions at a much lower concentration. Furthermore, the possible mechanisms of fluorescence quenching in the sensing process were systematically studied by PXRD, UV-vis, fluorescence decay lifetime, and density functional theory.