A Small-Molecule Fluorescent Probe for the Detection of Mitochondrial Peroxynitrite

Reactive oxygen species (ROS) are pivotal signaling molecules that control a variety of physiological functions. As a member of the ROS family, peroxynitrite (ONOO ) possesses strong oxidation and nitrification abilities. Abnormally elevated levels of ONOO can lead to cellular oxidative stress, which may cause several diseases. In this work, based on the rhodamine fluorophore, we designed and synthesized a novel small-molecule fluorescent probe ( ) for ONOO . Upon reaction with ONOO , exhibited a significant fluorescence signal enhancement (approximately 34-fold). Moreover, showed an excellent mitochondria-targeting capability. Confocal fluorescence imaging validated its ability to detect ONOO changes in HeLa and RAW264.7 cells. Notably, we observed the ONOO generation during the ferroptosis process by taking advantage of the probe. displayed good biocompatibility, facile synthesis, and high selectivity, and may have potential applications in the study of ONOO -associated diseases in biosystems.