A hydrazone-based turn-on fluorescent probe for peroxynitrite detection and live-cell imaging

Peroxynitrite (ONOO−) plays an important physiological role and is related to various clinical diseases. In the past two decades, a number of fluorescent probes have been developed to detect ONOO−, however, most of them show insufficient selectivity over other reactive oxygen species (ROS) and reactive nitrogen species (RNS), long response time, low fluorescence enhancement in the presence of ONOO−, and poor water solubility. Herein, a hydrazone-based fluorescent probe that overcomes the abovementioned problems was designed and synthesized by a single-step reaction. This probe exhibits high sensitivity to ONOO−, with ~76-fold enhancement of fluorescence intensity within 1 min, and excellent selectivity for ONOO− over various ROS/RNS. Furthermore, this probe was successfully applied for the visualization of ONOO− in RAW264.7 and H1299 cells.