A novel thiosemicarbazone Schiff base derivative with aggregation-induced emission enhancement characteristics and its application in Hg2+ detection

• Acenaphtho[1,2-b]quinoxaline-based thiosemicarbazone Schiff base (M1) was synthesized.
• Aggregation-induced emission enhancement (AIEE) properties of M1 were observed when the fraction of poor solvent was above 60%.
• “Turn-off” fluorescence alterations of M1 were observed upon the addition of Hg2+.
• Detection limits of Hg2+ reaches ∼ 0.9 μM.

A new acenaphtho[1,2-b]quinoxaline-based thiosemicarbazone Schiff base M1 has been designed and synthesized, which was characterized by FT-IR, 1H NMR, 13C NMR and HR-MS (TOF-MS). The properties of M1 were investigated by UV–vis absorption and fluorescence emission spectroscopy, founding that M1 possessed aggregation-induced emission enhancement (AIEE) properties and exhibited “on-off” fluorescent responses to Hg2+. The results of UV–vis and fluorescence titration experiments revealed that M1 was selective and sensitive to Hg2+ in DMSO/H2O (v/v = 9/1) buffered by 50 mM Tris-HCl at pH = 7.0. And the detection limit was calculated to be 9.07 × 10−7 M.