Preparation and Specific Detection of Zn2+ Ions of Polyacylhydrazones with Polymerization‐Induced Emission

Abstract Herein, inspired by the specific detection of the commercial dithizone to Zn 2+ , a series of polyacylhydrazones (PAHZs) with polymerization‐induced emission (PIE) properties are successfully prepared and applied to the specific recognition and detection of Zn 2+ . It is found that all selected monomers do not emit fluorescence. In contrast, the as‐prepared PAHZs can emit strong fluorescence at 455 nm, due to the intramolecular aggregation of acylhydrazone groups along the macromolecular chains, indicating a significant PIE effect. As it is expected, the PAHZs can specifically recognize and detect Zn 2+ ions from 17 metal ions by the significantly enhanced fluorescence with a lower limit of detection (LOD) of 66 nM. Additionally, the complexation ratio of 2:1 between the repeating units in PAHZs and Zn 2+ , the coordination of Zn 2+ with N and O atoms on acylhydrazone groups, and the fluorescence enhancement induced via intramolecular proton transfer are confirmed by 1H NMR and FT‐IR measurements. In conclusion, the successful preparation of PIE‐active PAHZs and the specific detection of Zn 2+ ions provide a useful reference for the molecular design of new functional materials on the base of the traditional detection methods.