A novel ratiometric and reversible fluorescent probe based on naphthalimide for the detection of Al3+ and pH with excellent selectivity. (7th February 2020) - Li, Zhuo
Abstract : A novel ratiometric and reversible fluorescence probe was designed and synthesized. The fluorescent probe recognizes Al 3+ to cause a blue shift in the fluorescence emission spectrum. Fluorescence probe can be used as a sensor to detect Al 3+ in living cells and Zebra fishes. The probe can detect the pH value when the alkalinity range was 8–10. Abstract : A novel ratiometric and reversible fluorescent probe, ( E )-2-butyl-6-hydroxy-5-(((2-(methylthio)phenyl)imino)methyl)-1 H -benzo[ de ]isoquinoline-1, 3(2 H )-dione (denoted as probe L ), based on naphthalimide and displaying excellent selectivity and hydrophilicity was designed and synthesized in order to be able to quickly identify Al 3+ . As the concentration of Al 3+ was increased, the probe L emission peak gradually shifted to a lower wavelength ( i.e., blue shifted) under single-wavelength excitation. And under UV light, a change in the fluorescence from green to blue was detected by the naked eye. The sensing mechanism was indicated to involve intramolecular charge transfer (ICT). The binding mode of L-Al 3+ was investigated by performing Job-plot and density functional theory (DFT) calculations. Probe L also showed a pH-response behavior: when the pH was increased from 8 to 10, the fluorescence intensity of the probe gradually increased, with a particularly good linear relationship. In addition, bioimaging investigations indicated that probe L is membrane permeable and that it can be used to identify Al 3+ in zebrafish and HeLa cells.