Sensing hydrogen peroxide involving intramolecular charge transfer pathway: A boronate-functioned styryl dye as a highly selective and sensitive naked-eye sensor

The synthesis, properties and applications of a novel boronate-functioned styryl dye, BSD, as a colorimetric sensor for hydrogen peroxide is presented. The dye displayed remarkable color change from colorless (λmax = 391 nm) to deep red (λmax = 522 nm) in the presence of H2O2 and the behavior could be rationalized by the chemoselective H2O2-mediated transformation of arylboronate to phenolate, resulting in the release of the merocyanine dye which featured with strong intramolecular charge transfer (ICT) absorption band. The absorption increment of merocyanine at λmax = 522 nm (ɛ = 87000 L mol−1 cm−1) is linear with the concentration of H2O2 in the range of 1.0 × 10−7–2.5 × 10−5 mol L−1 with the detection limit of 6.8 × 10−8 mol L−1 under optimum conditions. There is almost no interference by other species that commonly exist due to the specific deprotection of H2O2 towards arylboronate group on BSD. The chromogenic sensor has been applied to the detection of trace amounts of hydrogen peroxide in rain water.