Highly selective, sensitive and stable three-dimensional luminescent metal–organic framework for detecting and removing of the antibiotic in aqueous solution

Abstract

An efficiently selective sensor for aquatic antibiotic detection based on a photoluminescent cadmium metal–organic framework (Cd-MOF) is researched in this work. The novel and simple luminescent MOF that composed from a π-electron rich ligand bip (3,5-bis(1-imidazol) pyridine) and H3L (2-nitro-5-(4-carboxy-2-nitrophenoxy) isophthalic) was synthesized in hydrothermal condition and characterized. Single crystal X-ray diffraction analysis demonstrated that it had an uncommon 2-nodal (3,6)-connected 3D framework with a (32·4)(34·46·53·62) topology, which could be formulated as [{[Cd2(HL)2(bip)2]·H2O}n]. Benefiting from its unique framework, [{[Cd2(HL)2(bip)2]·H2O}n] can not only respond to the trace quantity of chloramphenicol (CHL) via fluorescence quenching but also show good adsorption capability toward CHL in aqueous solution. The selective response to CHL reached up to the ppb level with high anti-interference ability in aqueous phase, and the effective detection of antibiotics had been theorized by Density Functional Theory (DFT) calculation for energy bands of H3L and antibiotics, which revealed that the cooperation influence on photo-induced electron transfer (PET) process and fluorescence inner filter effect (IFE) made CHL show more sensitive luminescence responses than other experimental antibiotics. Moreover, because of its specific interactions with analytes and relatively high porosity, the pre-enrichment makes the antibiotic fuller contact and interact with the framework, which improves the overall sensing efficiency towards CHL appreciably. Stemming from the abuse, antibiotics have been considered as the great threat to the health of human race and the sustainable development of society. Therefore, it is extremely important to achieve new technology to detect and absorb antibiotics residues in water. This work proves that metal–organic framework complexes can conform the performance of detecting and removing antibiotic in aqueous environment, that emphasizes the application of luminescent MOFs in contaminant monitoring and removing.