Constructing fluorescence probes with fluoride-substituted donors for detecting •OH in living cells and zebrafish

Hydroxyl radicals (•OH) is one of the commonly reactive oxygen species available in biosystem and plays a key role in a number of physiological and pathological processes. Based on our previous study, fluoride could serve as a moderate electron donating group in constructing fluorescence probes. However, there is seldom work on the effects of fluoride-substituted moiety towards the photophysical properties in constructing fluorescence probes. In this work, we developed a series of novel fluorescence probes based on a quinolinium-scaffold containing fluoride substituted donor. From our results, the probe FHyR-3 which has an extended conjugated system could detect hydroxyl radical with high selectivity, sensitivity, and fast response. Furthermore, the probe has the maximum emission at 508 nm with a large stoke shift (114 nm) and exhibits low toxicity, good biocompatibility and mito-targeting. We also demonstrated its capability in tracking hydroxyl radical level in living cells and zebrafish.