Structurally controllable Cd(ii)-based luminescent metal–organic frameworks for efficient detection of antibiotics in water†

Abstract

Antibiotics have spread to natural waters due to their widespread use, posing a significant threat to the environment. It is of great importance to prepare sensing materials that enable rapid, simple and highly selective detection of antibiotics in water. Herein, two luminescent metal–organic frameworks (LMOFs) {[NaCd₂(bmipia)·Me₂NH₂]·5DMF·5H₂O}_n (FCS-7) and {[Cd₂(bmipia)·2Me₂NH₂]·8DMF·2H₂O}_n (FCS-8) were successfully prepared from Cd(II) ions and 5-N,N-bis(5-methylisophthalic acid) amino isophthalic acid (H₆bmipia), a semi-rigid carboxylic acid ligand, using a one-step solvothermal method. FCS-7 and FCS-8 exhibit different structural characteristics. Due to its stable three-dimensional (3D) topology and remarkable luminescence properties, FCS-7 can be used for the supersensitive detection of a wide range of antibiotics in water. Particularly noteworthy is that the fluorescence quenching constant of FCS-7 for nitrofurazolidone (NFZ) was as high as 121 170.44 M⁻¹, with a limit of detection (LOD) of 92 μg L⁻¹, whereas the fluorescence detection performance of FCS-8 was unsatisfactory. Furthermore, FCS-7 exhibits prominent anti-interference ability and good recyclability in the detection of NFZ.