A highly selective Cd(II) coordination polymer fluorescent probe for rapid detection of levofloxacin in water and milk

A new Cd(II) coordination polymer, {[Cd(L)(npht)]·4H₂O}_n <b>(1)</b> was successfully synthesized <i>via</i> hydrothermal method by 1,3-bis(5,6-dimethylbenzimidazol-1-yl)-2-propanol and 3-nitrophthalic acid as ligands. <b>1</b> expresses a double-annular shaped 1-D chain, which further extended into a 3-D supramolecular network through classic <i>π</i>···<i>π</i> stacking interactions. Based on the fluorescence resonance energy transfer (FRET) mechanism, <b>1</b> can be used as a promising fluorescence probe to detect levofloxacin (LEV) in water with limit of detection 2.1 × 10⁻⁸mol/L and achieved a rapid detection process within 30 s. Thanks to the excellent stability of <b>1</b> which can be soaked for a long time without damage and exhibits a very stable reuse effect. After four cycles of use, the detection rate of LEV is only 8% lower than the first time. The performance of <b>1</b> for determination of LEV in water and milk was also investigated. A stable Cd(II) coordination polymer {[Cd(L)(npht)]·4H₂O}_n (<b>1</b>) was hydrothermally synthesized and characterized. <b>1</b> served as a fluorescence sensor to detect levofloxacin in aqueous solution and milk.