A new indazole-based colorimetric chemosensor for sequential detection of Cu2+ and GSH in aqueous solution

Abstract A new selective and sensitive colorimetric chemosensor 1 was developed for the sequential detection of Cu 2+ and glutathione (GSH) in aqueous solution. The sensor 1 detected Cu 2+ ion by an obvious color change from colorless to pale yellow. Importantly, 1 could be used to detect and quantify Cu 2+ ion in water samples, and the detection limit (0.14 μM) of 1 for Cu 2+ was much lower than the guideline (31.5 μM) of WHO in drinking water. Also, Cu 2+ -2· 1 complex can be used as a colorimetric sensor for GSH via naked-eye. The detection limit for GSH was founded to be 2.98 μM. Moreover, the sensing ability of 1 for Cu 2+ was supported by theoretical calculations.