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

The hydroxyl radical ( OH), one of the most reactive and deleterious reactive oxygen species (ROS), has been suggested to play an essential role in many physiological and pathological scenarios. However, a reliable and robust method to detect endogenous OH is currently lacking owing to its extremely high reactivity and short lifetime. Herein we report a fluorescent probe HKOH-1 with superior in vitro selectivity and sensitivity towards OH. With this probe, we have calibrated and quantified the scavenging capacities of a wide range of reported OH scavengers. Furthermore, HKOH-1r, which was designed for better cellular uptake and retention, has performed robustly in detection of endogenous OH generation by both confocal imaging and flow cytometry. Furthermore, this probe has been applied to monitor OH generation in HeLa cells in response to UV light irradiation. Therefore, HKOH-1 could be used for elucidating OH related biological functions.