A novel displacement-type colorimetric chemosensor for the detection of Cu2+ and GSH in aqueous solutionElectronic supplementary information (ESI) available: Experimental procedures and additional experimental data. See DOI: 10.1039/c6ra12368f

A new and simple colorimetric chemosensor 1 was developed for the sequential detection of Cu 2+ and glutathione (GSH) in aqueous solution. Receptor 1 detected Cu 2+ ions by changing its color from colorless to yellow. Based on UV-vis titrations, Job plot, and ESI-mass spectrometry analysis, the sensing mechanism for Cu 2+ was proposed to be the enhancement of the intramolecular charge transfer band, which was further explained by theoretical calculations. The detection limit of 1 for Cu 2+ (3.89 μM) was below the World Health Organization (WHO) guideline for drinking water (31.5 μM). Moreover, the resulting 1 -Cu 2+ complex could sequentially sense GSH, showing recovery of 1 from the complex. A new selective and sensitive chemosensor 1 for the sequential detection of Cu 2+ and GSH via naked-eye has been developed.