A "Turn-on" Fluorescent Probe Based on Phenothiazine for Selectively Recognizing ClO^- and its Practical Applications

Hypochlorous acid (HClO), a highly reactive oxygen species, has important effects on human health. High selectivity and sensitivity remain challenges of fluorescent probes for detection of ClO^- with a large Stokes shift. This work designed and synthesized a novel phenothiazine-based fluorescent probe TF which can detect ClO^- by colorimetric and fluorescent dual signals. TF displayed turn-on fluorescence effect toward ClO^- with high selectivity (≥ 28-folds) and sensitivity (LOD = 0.472 μM), fast response time (< 1 min) and large Stokes shift (150 nm) in PBS (pH = 7.4, 40% DMSO). Meanwhile, TF can visualize ClO^- on the mung bean sprouts model and apply as testing strips for portable and rapid detecting ClO^- by the naked eyes. A phenothiazine-based fluorescent probe with large Stokes shift was synthesized and its responding rapidly ability to detect ClO^- was studied.