Highly Selective Naked-Eye and Fluorescence Probe for Cu2+ Based on Carbazole Schiff-Base

A new fluorescence probe L based on carbazole Schiff-base for Cu2+ was synthesized. The recognition ability of probe L to metal ions was investigated by UV-Vis and fluorescence spectra. The experimental results showed that the probe L in CH3CN displayed a distinct color change from yellow to colorless upon the addition of Cu2+, which can be directly detected by the naked eye for Cu2+. The fluorescence spectra showed that the probe L had high selective and sensitive recognition toward Cu2+ in CH3CN, the fluorescence intensity was increased with the increase of Cu2+ concentration, and it was not affected by other metal ions. The association constant between the probe L and Cu2+ was detected to be 1.38x10(4) L/mol and the corresponding detection limit was calculated to be 2.34x10(-7) mol/L. The detection limit of L for Cu2+ was far lower than the maximum allowable level of the WHO limit (20. mol/L) for drinking water. The results indicate that the probe L should be applicable to the research on the environmental applications associated with Cu2+.