A triazole Schiff base-based selective and sensitive fluorescent probe for Zn2 +: A combined experimental and theoretical study

•A simple but effective fluorescence sensor for Zn2 + was investigated.•The detection limit of HL for Zn2 + could reach at 10− 8M level.•The mechanism of HL for detecting Zn2 + was evaluated by TD-DFT calculations.

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. Time-dependent density functional theory (TD-DFT) calculations indicate that a chelation-enhanced fluorescence (CHEF) effect occurs in the process of detecting Zn ion.

Graphical abstractA simple but high selectivity and sensitivity fluorescent sensor for Zn2 + based on triazole Schiff base was reported using the combined experimental and theoretical study methods.Figure optionsDownload full-size imageDownload as PowerPoint slide