A new selective fluorescent and colorimetric chemosensor for the detection of GSH was developed. The discrimination of GSH from Cys and Hcy is achieved through two emission channel detection. The detection limit of probe 1 for GSH reached 10 nM (3 ppb). The excellent sensitivity and selectivity of probe 1 allow the selective detection of GSH over Cys and Hcy, which can be visualized colorimetrically and/or fluorescently. The sensitive detection of GSH allowed for convenient measurement of the GSH content in human plasma. The presence of GSH in cells was demonstrated through cell imaging.