New pyrrole-based single-molecule multianalyte sensor for Cu2+, Zn2+, and Hg2+ and its AIE activity

An aggregation-induced emission (AIE) active bis-hydrazone in the aqueous medium is designed and prepared, which can be used as a multi-probe that selectively detects Cu2+, Zn2+, and Hg2+ by monitoring the changes in absorption and fluorescence spectral patterns. Results show that Zn2+ and Hg2+ can enhance the fluorescence in EtOH solution. The addition of Cu2+ strongly improves absorption in the visible range. In contrast to the fluorescence of 1 + Zn2+, the fluorescence of 1 + Hg2+ can be maintained in the presence of water. The crystal structure of the Hg(II) complex based on 1 is further determined through X-ray crystallographic analysis. To test the practical use of the probe, the determination of Hg2+ in real water samples was also evaluated.