A two-fold interpenetrated 2D Zn (II) coordination polymer for sensitive and stable sensing of Fe3+/nitrofurantoin

Abstract

Rapid, sensitive and stable detection of antibiotics and heavy metal ions in water system is essential for human health. A two-fold interpenetrated 2D Zn (II) coordination polymer (CP) [Zn(BIPY)(bibp)]n (H2BIPY = 6-(5-carboxypyridin-2-yl) pyridine-3- carboxylic acid], bibp = 4,4′-bis (imidazolyl) biphenyl) has been designed by a rigid ligand and zinc nitrate. The excellent thermodynamic stability of Zn-CP can be confirmed by thermogravimetric (TG) and powder X-ray diffraction (PXRD) analyses. Meanwhile, fluorescence sensing experiments displayed Zn-CP can sensitively sensing of Fe3+/nitrofurantoin (NFT) with limit of detection of 1.33 μM/0.84 μM. The sensing mechanisms of Zn-CP for Fe3+/NFT are attributed to competitive absorption and static quenching between Zn-CP and Fe3+/NFT, and electron transfer from Zn-CP to NFT, which can be confirmed by patterns of PXRD, ultraviolet visible (UV–vis) spectra, fluorescence lifetime decay experiments, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. In addition, anti-interference experiments and cyclic experiments showed that Zn-CP have excellent fluorescence sensing selectivity and stability for Fe3+/NFT.