A two-photon NIR-to-NIR fluorescent probe for imaging hydrogen peroxide in living cells

Hydrogen peroxide (H2O2), one of the reactive oxygen species (ROS), plays vital roles in diverse physiological processes. Imbalance of the H2O2 is concerned with serious diseases such as cardiovascular disorders, neurodegenerative diseases, Alzheimer's disease and cancer. Therefore, it is critical to develop efficient methods for monitoring H2O2 in vivo. In this work, a two-photon excitation (860nm) NIR fluorescent turn-on probe TPNR-H2O2 for H2O2 based on Dicyanomethylene-4H-pyran fluorophore is reported, which can be used in solution detection with 13.2-fold NIR fluorescence enhancement, fast response (completed within 40min), excellent sensitivity (DL 72.48nM), and lower cellular auto-fluorescence interference. Importantly, the perfect photostability of TPNR-H2O2 clearly demonstrated that the probe could be applied to imaging intracellular H2O2 for a long time without photobleaching. In addition, through two-photon imaging, this probe was cell permeable and used to monitor the level of endogenous and exogenous H2O2 with promising biological application. [Display omitted] •An NIR fluorescent probe for the detection of H2O2 using two-photon excitation is reported.•The detection limit (3σ/k) toward H2O2 was calculated to be 72.48nM.•Probe TPNR-H2O2 could be used to monitor H2O2 dynamic changes in vivo for a long time without photo-bleaching.•Probe TPNR-H2O2 was preferably applied to the detection of endogenous H2O2 in vivo via two-photon fluorescence imaging.