Synthesis and Application of Specific NH Fluorescent Probes with AIE Effect Based on Pyrazole Structure.

Two fluorescent probes, Y were synthesized from 2-acetonaphthone, 4-acetylbiphenyl, and phenyl hydrazine by Vilsmeier-Haack reaction and Knoevenagel condensation. Their recognition efficacies for NH were tested by UV-visible absorption spectroscopy and fluorescence emission spectroscopy. The recognition mechanism were studies by density-functional theory calculations, and the effect of pH on NH recognition was also studied. The results showed that the probe Y has high selectivity and a low detection limit for NH, and the recognition of NH can be accomplished at physiological pH. The probes have had obvious aggregation-induced luminescence effect, large Stokes shift, high sensitivity, and can be successfully applied to live cell imaging.