Trinuclear Cobalt/Nickel-Based Metal-Organic Frameworks as Fluorescent Sensor Toward Quinolone Antibiotics

The leakage of quinolone antibiotics may bring serious hazards to plants, animals, and human; thus, the detection of quinolone antibiotics is of great urgent yet remains challenging issue. Herein, two isostructural metal-organic frameworks {[(CH3)(2)NH2](2)[M-3(mu(3)-O)(BPDC)(3)(TPP)]<middle dot>xMeCN<middle dot>yDMF}n (M = Co, x = 8, y = 1, NS-13; M = Ni, x = 7, y = 1, NS-14; H2BPDC = 4,4 '-biphenyldicarboxylic acid; TPP = 2,4,6-tris(4-pyridyl)pyridine), have been successfully prepared through solvothermal method. NS-13 and NS-14 were three-dimensional networks built form [M-3(mu(3)-O)](4+) clusters. Impressively, both NS-13 and NS-14 displayed good fluorescence response to norfloxacin, ofloxacin, and enrofloxacin with low limit of detection (LOD) and excellent recyclability, to our best knowledge, which are superior to most of reported metal-organic frameworks. Furthermore, density functional theory (DFT) calculations and fluorescence lifetime experiments uncovered the possible fluorescence probe mechanism of NS-13 and NS-14 toward the above-mentioned quinolone antibiotics. This work extends the application of cluster-based metal-organic frameworks in the detection of antibiotics.