A [Co5] cluster-based organic framework as fluorescent detection platform toward quinolone antibiotics

The detection of quinolone antibiotics is an important research hotspot for protecting human health. Herein, a three-dimensional metal-organic framework with the formula of {[Co-5(TPT)(2)(BPDC)(3)(mu(3)-O)(2)(H2O)(4)]<middle dot>8MeCN<middle dot>3DMF}(n) (NS-3, TPT = tris(4-pyridyl)-1,3,5-triazin, H2BPDC = 1,4-benzenedicarboxylic acid) has been successfully prepared through solvothermal method. Single-crystal X-ray diffraction analysis revealed that three-dimensional NS-3 can be viewed as an eight-connected sqc4 net with pentanuclear [Co-5(mu(3)-O)(2)](6+) cluster as metal nodes. Importantly, when norfloxacin, ofloxacin, and enrofloxacin were added in NS-3 ethanol suspension, the luminescence intensity of NS-3 at 333 nm was obviously decreased while new emission peaks clearly emerged, indicating that NS-3 can be a potential rare fluorescent detection to recognize quinolone antibiotics in ethanol. Additionally, NS-3 exhibits high sensitivity to norfloxacin, ofloxacin, and enrofloxacin with a limit of detection of 43, 34, and 139 nM, respectively, which is superior to most of the reported metal-organic frameworks.