A novel quinoline-based turn-on fluorescent probe for the highly selective detection of Al (III) and its bioimaging in living cells, plants tissues and zebrafish.

A novel quinoline fluorescent probe QNP ((E)-N'-(5-chloro-2-hydroxybenzylidene) quinoline-2-carbohydrazide) for detection of Al ion was designed, synthesized and characterized. QNP displayed a high fluorescence enhancement in the presence of Al ion in DMF:PBS (99:1, v/v) solution and the detection limit was as low as 1.25 μM with high selectivity and excellent sensitivity from 0 to 3 μM. The sensing ability of QNP towards Al ion is attributed to the synergistic effect of PET and ICT. Furthermore, the binding stoichiometry between QNP and Al ion is of 1:1 by Job's plot and mass spectrum, and the calculated binding constant is 4.29 × 10 M. The detection of Al ion in water samples illustrates that QNP could be applied to the detection of practical samples in the environment. Bioimaging experiments on Hela cells, zebrafish and soybean root tissues demonstrate that it has potential application to investigate biological processes involving Al ion within living cells. A quinoline-based turn-on fluorescence probe for the detection of Al and its bioimaging in living cells, plant, and zebrafish.