Two robust Zn(II)-organic frameworks as dual-functional fluorescent probes for efficient sensing of enrofloxacin and MnO4- anions

Selective detection of antibiotics and MnO4- is crucial for human health improvement and protecting the environment. Two stable Zn(II)-based metal-organic frameworks (MOFs) {[Zn-6(L1)(2)(NDC)(5)(mu(2)-OH)(2)]center dot 0.5H(2)O}(n) (1), and {[Zn(L2)(NDC)]center dot 2H(2)O}(n) (2) (H2NDC = 1,4-naphthalenedicarboxylic acid, L1 = 1,5-bis(1-(pyridine-4-ylmethyl)-1H-benzo[d]imidazol-2-yl)pentane, L2 = 1,6-bis(1-(pyridine-4-ylmethyl)-1H-benzo[d]imidazol-2-yl)hexane) were successfully synthesized by adopting the mixed ligands approach. 1 is a rare 3D 3,5,6T23 framework based polynuclear complex group. 2 possesses a 2D sql layer. The two MOFs exhibit excellent chemical and thermal stability. The title compounds are promising dual-functional fluorescent sensors for detecting enrofloxacin/MnO4- anions with high selectivity and sensitivity (K-sv values toward enrofloxacin: 4.29 x 10(6) L mol(-1) for 1 and 4.59 x 10(6) L mol(-1) for 2 and toward MnO4-: 1.05 x 10(4) for 1, 5.48 x 10(3) L mol(-1) for 2, respectively), which are the first observations of fluorescent MOFs for the sensing of enrofloxacin and MnO4- anions.