A colorimetric, ultraviolet absorption and fluorescence three-signal probe based on bis-carbazole for Al3+ detection and the application in cell imaging

摘要： A novel Schiff-base, [9-(2-Chloro-ethyl)-9H-carbazol-3-yl-methylene]-(9-ethyl-9H-carbazol-3-yl)-amine (CECA) was designed and synthesized, which was highly selective and sensitive for the detection of Al3+ by colorimetric, ultraviolet absorption and fluorescence three-signal methods. The detection limit was evaluated to be as low as 74 nmol/L for the ultraviolet absorption method and 19 nmol/L for fluorometric method. These three methods could determine qualitatively and quantitatively the concentrations of Al3+ and been used in different conditions. The mechanism was explored that the double bond (C=N) of CECA was broken to form the carbazole aldehyde and carbazole amine complex accompanied by fluorescence enhancement by the Job's plot, 1H NMR, the electrospray ionization mass spectra (EI-MS) and fluorescence methods. More significantly, the fluorescence imaging showed that CECA could detect Al3+ in living cells.