A new colorimetric and fluorescent chemosensor based on thiazolyl-hydrazone for sensitive detection of copper ions

A Cu2+-specific chemosensor probe thiazolyl-hydrazone (BL) has been designed and prepared, which provide tridentate chelate NNO coordination mode for Cu2+ with binding stoichiometry of 1:1. The BL solution exhibits a rapid color change from colorless to yellow along with a new intense absorption band at 414 nm upon binding to Cu2+ cation, whereas other metal cations do not induce such a change. The analytical detection limit is 0.75 μM, and the naked eye detection limit is as low as 20 μM. Additionally, the emission signal of BL could be quenched by Cu2+ and Fe3+ with a detection limit of 7.2 μM and 4.3 μM, respectively.