A novel fluorescent metal-organic framework based on porphyrin and AIE for ultra-high sensitivity and selectivity detection of Pb2+ ions in aqueous solution

Lead (Pb2+) ion, as a heavy metal pollutant in water, is harmful to human health, and may cause various diseases. Therefore, it is of great necessity for people to find a new and quick way to detect Pb2+ ions in water. Based on this condition, a zinc porphyrin-based metal-organic framework (ZnTCPP-MOF) with aggregation-induced emission (AIE) was successfully synthesized via coordination polymerization of zinc (Zn2+) ions, H2TCPP and TPE-2COOH, and shows a great fluorescent phenomenon which can be used as a fluorescent probe to detect metal ions in aqueous solution. So, the ZnTCPP-MOF with a highly selective and sensitive property can be employed to detect Pb2+ ions. The experiment results exhibit that the color change of ZnTCPP-MOF could be directly discovered from bright red to colorless after adding Pb2+ ions by naked eyes. Meanwhile, the quenching curves, at lower concentrations of Pb2+ ions, exhibited an excellent linear relationship between fluorescence quenching efficiency and concentrations. The highlight of this study is that the ZnTCPP-MOF could explore Pb2+ ions in water, at very low concentrations, as well as the limit of detection (LOD) is 4.99 × 10−8 M which is an excellent data, compared with other MOFs.