A novel flexible V-shaped dicarboxylate Eu-based MOF for multifunctional fluorescent detection of Fe3+, MnO4− and nitrofurantoin and mechanistic study

Industrial emissions of heavy metal ions and oxygen-containing anions, antibiotic residues caused by pharmaceutical and agricultural activities, and toxic ions such as Fe 3+ introduced by nuclear industry leaks, collectively form a complex water pollution. Here, we report the successful synthesis of a novel europium-based metal-organic framework (Eu-MOF) through a hydrothermal approach employing a flexible V-shaped dicarboxylic acid ligand. The single crystal X-ray diffraction results indicate that the Eu-MOF belongs to the orthorhombic crystal system. Its basic structural unit is a one-dimensional coordination chain, which is further assembled by hydrogen bonding and π - π stacking between molecules, ultimately forming a stable three-dimensional supramolecular structure. Leveraging the intense red emission of Eu 3+ and its robust structural integrity, the Eu-MOF demonstrates remarkable sensitivity and specificity in the fluorescence detection of Fe 3+ , MnO 4 − , and nitrofurantoin (NFT) in aqueous solutions, featuring low detection limits and substantial quenching constants. Mechanism studies have shown that the structure of the material remains stable during the sensing process, and fluorescence quenching is mainly caused by the combined effects of static quenching, competitive absorption, and photo-induced electron transfer. This research introduces a dependable multifunctional luminescent platform for the swift and precise monitoring of various hazardous environmental contaminants.