A facile and highly selective "turn-on" fluorescent chemodosimeter for Hg2+and its AIE activity

An aggregation-induced emission (AIE) active anthracene-based fluorescent chemodosimeter, anthracene-9carbaldehyde hydrazone (ACH), was synthesized via a facile one-step reaction from anthracene-9carbaldehyde (AC) and hydrazine monohydrate. The structure of probe ACH was completely characterized by a variety of methods, including MS, 1H NMR, 13C NMR, FT-IR, and elemental analysis. The probe ACH showed high specificity and excellent sensitivity for Hg2+ in MeOH-water (9/1, v/v) solution, which exhibited an obvious fluorescence "turn-on" change with a mega Stokes shift of 157 nm (& lambda;Ex = 256 nm, & lambda;Em = 413 nm) and a low detection limit of 5.67 x 10-8 M. Studies of the sensing mechanism indicated that the fluorescence "turn-on" response was presumably owing to the Hg2+-promoted hydrolysis reaction of ACH to provide the intensely fluorescent AC. It was worth noting that the reaction-based probe could be successfully used to detect the concentration of Hg2+ in real water samples and distinguish Hg2+ on the filter papers and TLC plates. We expect this work can stimulate the emergence of preferable fluorescent chemodosimeter for practical application.