Benzoyl Peroxide Detection in Real Samples and Zebrafish Imaging by a Designed Near-Infrared Fluorescent Probe.

A novel near-infrared fluorescence off-on probe, (E)-3,3-dimethyl-1-propyl-2-(2-(6-(2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyloxy)-2,3-dihydro-1H-xanthen-4-yl)vinyl)-3H-indolium (1), is developed and applied to benzoyl peroxide (BPO) detection in real samples and fluorescence imaging in living cells and zebrafish. When arylboronate as the recognition unit is connected to a stable hemicyanine skeleton, the probe is readily prepared, which exhibits superior analytical performance, such as near-infrared fluorescence emission over 700 nm and high sensitivity with a low detection limit of 47 nM. Upon reaction with BPO, phenylboronic acid pinacol ester is oxidized, followed by hydrolysis and 1,4-elimination of o-quinone methide to release fluorophore. In addtion, the probe displays high selectivity toward BPO over other common substances, which makes it of great potential use in quantitative and simple detection of BPO in wheat flour and antimicrobial agent. More importantly, the probe has been successfully demonstrated for monitoring BPO in living HeLa cells and zebrafish. The probe with superior properties could be of great potential use in other biosystems and in vivo studies.