A luminescent Zn(II) metal-organic framework assembled with a thiazolothiazole chromophore for sensing mainly cobalt(II) and nitrofuran antibiotics in aqueous solutions

The accumulation of cobalt(II) and antibiotics in the environmental water system has posed a significant threat to both human health and the safety of the ecological environment. Therefore, it is of utmost importance to look for a proficient means to detect cobalt(II) and antibiotics. Herein, we introduce a luminescent Zn-MOF, constructed with a thiazolo[5,4-d]thiazole ligand that features a chromophore group, which serves as a sensor to detect cobalt(II) and antibiotics. The Crystal structure of {[Zn2(OBA)2(4bpyttz)].2DMF} (1) (4bpyttz=2,5-bis(pyridine-4-yl)thiazolo[5,4-d]thiazole, H2OBA=4,4 '-oxybis(benzoic acid)) displayed a 6-c net three-dimensional (3D) framework structure with novel topological type denoted as {44.610.8}. Moreover, luminescence sensing studies demonstrated that 1 exhibits high selectivity and multi-responsiveness of multiple ions mainly for Co2+, and nitrofuran antibiotics mainly for NZF, and NFT in an aqueous medium inducing turning-off effects. The detection limits are determined to be 1.14, 0.14, and 0.072 mu M for 1, respectively. Additionally, MOF-derived fluorescence test papers and composite films were utilized for the visual detection of Co2+, NZF, and NFT, thereby expanding the potential applications of the system in real-world sensing. Furthermore, the potential luminescence quenching mechanism of MOF 1 regarding Co2+ ions and nitrofuran antibiotics could be deduced through various characterization methods.