Pyrene-acylhydrazone-based Turn-on Fluorescent Probe for Highly Sensitive Detection Cu2+ and Application in Bioimaging

The development of highly selective and sensitive, low detection limits, and biocompatible turn-on copper ion fluorescent probes is of great significance for the environment and life sciences. In this study, a novel turn-on fluorescent probe T based on pyrene-acylhydrazone was synthesized via an efficient one-step condensation reaction and characterized by 1 H NMR, 13 C NMR and HRMS. The probe T exhibited high selectivity with a low detection limit of 0.304 nM towards Cu 2+ in DMSO/H 2 O (v/v = 1 : 1) medium by a PET-TICT dual interplaying sensing mechanisms. Job's plot analysis and HRMS data confirmed the 1 : 1 binding stoichiometry between T and Cu 2+ with an association constant of 5.7×10 3 M -1 . Additionally, the binding model was investigated by 1 H NMR titration and FT-IR spectra. Furthermore, probe T exhibits low cellular toxicity and excellent membrane permeability, and has been successfully applied for fluorescent imaging of copper ions in live HT-22 cells.