Visual and portable detection of metronidazole realized by metal-organic framework flexible sensor and smartphone scanning

Metronidazole (MNZ) is a type of antibiotic that can help people and animals cure bacterial infections, however, abuse of MNZ has posed a threat to human health. Hence, portable and visual detection of MNZ is meaningful for food safety and rational administration of drugs, but full of challenges. Hence, a porous three-dimensional Tb-based metal-organic framework (MOF) {(CH3)2NH2·[Tb5(TDA)8(H2O)2]·6DMF·2C2H5OH}n (TDA-Tb) with good solvent and pH stabilities was prepared, and the framework possesses one-dimensional channels with a diameter of 12 Å along the c-axis. Experiment results suggest that the synthesized TDA-Tb can selectively and sensitively detect MNZ in water, and the limit of detection (LOD) is as low as 4.1 × 10−7 mol/L. Moreover, a flexible sensor TDA-Tb-M was also constructed by incorporating TDA-Tb into membrane materials for convenient usage. And the TDA-Tb-M firstly realized portable and visual detection of MNZ through smartphone scanning, which may inspire more probes with wide application ranges.