A triazole Schiff base-based selective and sensitive fluorescent probe for

    A triazole-Schiff base, 4-(5-Chloro-2-hydroxybenzylideneamino)-1H-1,2,4-triazole-5(4H)-thione (HL), exhibits the high selectivity and sensitivity for Zn2+ in the fluorescence spectrometry over other common metal ions, especially Cd2+ in DMSO:H2O (1:9, v/v) solution. A 1:1 binding ratio of Zn2+/L for the complex has been obtained by Uv–Vis titration experiments and Job's plot with the detection limit of 51 nmol/L. The coordination mode of the complex in solution was further confirmed by density functional theory (DFT) calculations. Timedependent density functional theory (TD-DFT) calculations indicate that a chelation-enhanced fluorescence (CHEF) effect occurs in the process of detecting Zn ion.