Ratiometric Fluorescent Probe for Sensitive Tracking of Peroxynitrite during Drug‐Induced Hepatotoxicity

As an essential component of reactive oxygen species (ROS), peroxynitrite (ONOO^-) plays an indispensable role in redox homeostasis and signal transduction, with anomalous levels implicated in various clinical conditions. Therefore, accurate and rapid detection of intracellular ONOO^- levels is crucial for revealing its role in physiological and pathological processes. In this study, we developed a ratiometric fluorescent probe to detect ONOO^- levels in biological systems. The probe demonstrated a fast reaction rate (within 15 min), outstanding selectivity, high sensitivity (limit of detection=13.32 nM), and stability in the presence of ONOO^-. The proposed probe was successfully used for visualizing endogenous ONOO^- in living cells and tracking changes in intracellular ONOO^- levels during drug-induced hepatotoxicity using ratiometric fluorescence.