Merocyanine Dye-Based Fluorescent Chemosensor for Highly Selective and Sensitive Detection of Hypochlorous Acid and Imaging in Live Cells

摘要

A merocyanine dye-based fluorescent probe have been synthesised for selective and sensitive detection of hypochlorous acid. The merocyanine dye 1 can be synthesized by simple condensation reaction of 1, 1, 2, 3-tetramethyl-1H-benzo[e]indol- 3-ium iodide with indole-3-carboxaldehyde. The reaction between hypochlorous acid and dye 1 is linear in the hypochlorous acid concentration range of 0 to 100 mM with a detection limit of 42 nM by fluorescent spectrometry method. The intramolecular charge transfer based fluorescent probe dye 1 displayed a considerable fluorescent spectrum at 425 nm enhancement and the color changes from red to colorless by naked eye detection in the addition of hypochlorous acid. Further supported by the ~1HNMR titrations reveal that the reactive oxygen species in dye 1 bind to the indole-NH-unit. The chemosensor also showed excellent performance when used in the "test strip" method.