Dual NIR-channel fluorescent probe for detecting ONOO− in vitro and vivo

[Display omitted] •An optical and dual NIR-channel fluorescent sensor for ONOO− was prepared.•The sensor showed a dual-emission fluorescent response (660 and 800 nm) upon the addition of ONOO−.•The dual-channels imaging of exogenous and endogenous ONOO− in live cells and zebrafish was successfully performed. As one of endogenous reactive oxygen species (ROS), peroxynitrite (ONOO−) performs various functions in both pathological and physiological mechanisms. In this work, an optical and near-infrared (NIR) fluorescent probe (NX), which based on 3-dihydro-1H-xanthene and 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) group was designed and prepared to detect ONOO−. This probe revealed an obvious optical and a fluorescent response when ONOO− was present and it exhibited higher selectivity over other ROS. Especially, the dual NIR fluorescence changes at 660 and 800 nm allowed quantitative detection of ONOO− in the range of 15–40 μM, and the detection limit was 82 nM. Finally, the probe was effectively employed to visualize exogenous and endogenous ONOO− in HepG2 cells and zebrafish, respectively. All the results indicated the dual NIR-channel probe could serve as a potent detecting tools in studying ONOO− in vitro and in vivo.