A Red-Emitting Fluorescence Probe for Rapid Detecting Exogenous and Endogenous Peroxynitrite in Living Cells with High Sensitivity and Selectivity

Peroxynitrite (ONOO−) has been revealed to play crucial roles in many physiological and pathological processes, and many diseases were proven to be associated with its misregulated production. The development of fluorescent probes meets the need for tracking ONOO− and gives a better understanding of its diverse mechanisms. In this work, a red-emitting fluorescent probe BP-ONOO was synthesized via functionalization of the rhodol-like fluorophore with a reactive site of hydrazide. The probe BP-ONOO exhibited high sensitivity, excellent selectivity, and short response time (less than 4 s) towards ONOO− under neutral or weak alkaline conditions. These attractive properties favor its application in real-time imaging of ONOO− in living cells, and the probe has been successfully applied for imaging the concentration levels of ONOO− in RAW 264.7 macrophage cells under drug stimulation.