A carbazole-functionalized metal–organic framework for efficient detection of antibiotics, pesticides and nitroaromatic compounds

Organic pollutants, such as antibiotics, pesticides, and nitroaromatic compounds (NACs), have posed a great threat to human health and sustainable development. Therefore, the detection of these organic pollutants is of great importance but challenging. In this work, we synthesized a rigid conjugated tricarboxylic acid ligand 4,4'-(9-(4'-carboxy-[1,1'-biphenyl]-4-yl)-9H-carbazole-3,6-diyl)dibenzoic acid (H3CBCD), and employed this ligand to react with Cd(ii) ions to construct a Cd-LMOF, namely [Cd3(CBCD)2(DMA)4(H2O)2]·10DMA (Cd-CBCD). Cd-CBCD features a three-dimensional (3D) supramolecular framework based on two-dimensional (2D) layer structures through ππ stacking interactions. The fluorescence sensing measurements demonstrate that Cd-CBCD can detect nitrofurans (NFs), 4-nitroaniline (4-NA) and 2,6-dichloro-4-nitroaniline (DCN) with high selectivity and sensitivity. This work represents the first carbazole-functionalized metal-organic framework as a fluorescent sensor for the highly efficient detection of antibiotics, pesticides and nitroaromatic compounds.