A near-infrared fluorescence probe for ultrafast and selective detection of peroxynitrite with large Stokes shift in inflamed mouse models

Peroxynitrite (ONOO−) is a kind of reactive oxygen species (ROS) which is associated with pathogenesis of many diseases. A new near-infrared fluorescence probe (DCM-OH) which based on dicyanomethylene-4H-pyrans to detect endogenous ONOO− was designed and synthesized. The two-photon absorption cross sections and large Stokes shift make the probe deeper issue penetration and lower self-absorption. The obtained results demonstrated that probe DCM-OH could sensitively detect ONOO− with a low detection limit (53 nM). What's more, probe DCM-OH exhibited an ultrafast response rate (within 5 s) toward ONOO−, which would be in favor of tracking the highly reactive and short-lived ONOO− in the living systems. Moreover, DCM-OH was successfully employed for imaging endogenous ONOO− in HepG2/RAW 264.7 cells and further applied to visualize oxidative stress in mouse model of inflammation.