Four Zn(II)-MOFs as Highly Sensitive Chemical Sensor for the Rapid Detection of Tetracycline, o-Nitro Phenol, Cr2O72– /PO43–, Fe3+/Al3+ in Water Environment

Uncontrolled industrialization not only caused irreparable damage to the surrounding ecological environments, especially water resources, but also seriously threatened human health. How to sensitively detect toxic pollutants in the hydrological system is a prerequisite for protecting human life. The luminescent metal–organic frameworks (LMOFs) have excellent applications in this field. Herein, four Zn-MOFs, namely [Zn3(dpcp)2(1,4′-bmib)2]n (1), {[Zn4(dpcp)2(4,4′-bibp)2(μ2-O)4]·3H2O}n (2), [Zn(2-ata)(bidpe)]n (3), and [Zn(bbibp)(HCOO)2]n (4) (dpcp = 3-(3,5-dicarboxylphenoxy)-5-carboxylpyridine, 2-ata = 2-aminoterephthalic acid, 1,4′-bmib = 1,4-bis(2-methylimidazol-1-yl) butane, 4,4′-bibp = 4,4′-bis(imidazolyl) biphenyl, bbibp = 4,4′-bis(benzoimidazo-1-ly) biphenyl, bidpe = 4,4′-bis(lmidazolyl)diphenyl ether), were synthesized by solvothermal method and characterized by single crystal X-ray diffraction. For tetracycline, o-nitro phenol, Cr2O72– and Fe3+, 1–4 have different degrees of fluorescence quenching effect and exhibit good sensitivity and high-selective detection of the above analytes in the presence of multiple interference species (such as antibiotics, amino acids, metal ions and inorganic ions). Additionally, the heat map and principal component analysis plot visually represent the selective detection effect of Fe3+, Cr2O72– and tetracycline by 1–4. Besides, 3 can detect PO43– and Al3+ independently with high selectivity from homogeneous pollutants through the fluorescence enhancement phenomenon. This work offers insight into exploring the potential applications of zinc-based MOFs in the chemical sensing field.