Fluorogenic boronate-based probe-lactulose complex for full-aqueous analysis of peroxynitrite

A selective fluorogenic boronate-based probe-lactulose complex was evaluated for the rapid analysis of peroxynitrite (ONOO^-) based on a reaction-based indicator displacement assay (RIA). The probe was synthesised by a simple nucleophilic substitution reaction between a boronic acid moiety and a well known laser dye, DCM. Fluorescence analyses showed that the probe had an off-on response to lactulose, forming a fluorogenic probe-lactulose complex. The subsequent addition of ONOO^- selectively quenched the fluorescence of the complex over other Reactive Oxygen/ Nitrogen Species (ROS/RNS) tested. The complex can be applied for the rapid determination of ONOO^- in full aqueous solution with good linear range, and has also proven suitable for monitoring ONOO^- in living cells and real water samples.