HKOH-1: A Highly Sensitive and Selective Fluorescent Probe for Detecting Endogenous Hydroxyl Radical in Living Cells

Hydroxyl radical (●OH), one of the most reactive and harmful reactive oxygen species (ROS), has been suggested to play an essential role in a lot of physiological and pathological scenarios. Development of fluorescent probes for •OH is highly challenging due to its extremely high reactivity and short lifetime. Here we report a fluorescent probe HKOH-1 with superior in vitro selectivity and sensitivity towards •OH. With this probe, we have calibrated and quantified a wide range of reported •OH scavengers. In addition, HKOH-1 has performed robustly in detection of endogenous •OH generation in multiple cellular models under the settings of both confocal imaging and flow cytometry. Furthermore, this probe has been applied to monitor •OH generation in several types of cells in response to UV light irradiation. Therefore, HKOH-1 could serve as a promising tool for elucidating the •OH-related biological functions.