A o-phenanthroline-based metal-organic framework for fluorescence sensing toward Cr^VI and antibiotics in aqueous phase

Herein, a novel o-phenanthroline-based ligand involving two naphthalenecarboxylate groups was first synthesized, and successfully employed to fabricate a fluorescent metal–organic framework 1 under solvothermal conditions. According to the single-crystal X-ray analysis of compound 1, the Cd(II) ions connected by organic ligands form a 2D layer structure with a unique metallacycle building unit, and adjacent 2D layers are further stacked into a 3D porous framework via numerous supramolecular interactions. Powder X-ray diffraction revealed that 1 exhibits exceptional stability in both water and common organic solvents. The fluorescence sensing experiments conducted with compound 1 toward anions and antibiotics, demonstrated its selective detection capabilities for Cr^VI anions (CrO₄²⁻/Cr₂O₇²⁻) and nitrofuran antibiotics in aqueous solutions. Additionally, fluorescent 1 serves as an effective fluorescent probe for sensing nitro-aromatic compounds in dimethyl sulfoxide. Its robust anti-interference properties, recyclability, and resistance to water make compound 1 a promising candidate for pollutant detection in wastewater.