Selective and Sensitive Fluorescence Chemosensor for the Hypochlorite Anion in Water

Abstract

Based on an oxidized irreversible ring-opening process of the spirolactam of rhodamine 6G to turn on the fluorescence pathway, a highly sensitive, selective fluorescent and easy accessible chemosensor for ClO(-) has been reported. Upon reaction of the chemosensor with ClO(-) ions, a fluorescent enhancement factor over 60-fold is observed. The chemosensor shows a remarkably high selectivity to discriminate between ClO(-) and other ROS, such as H(2)O(2), TBHP etc., and a wide range of the environmentally and biologically relevant anions and metal ions. The oxidized irreversible ring-opening process of the chemosensor also triggers a visible colorimetric change from colorless to pink, leading to production of both "naked-eye" and fluorimetric detection of ClO(-) anion. The detection limit is estimated to be 2 × 10(-8) M based on a signal-to-noise ratio of 3:1 method. The chemosensor can be used within a pH span of 6-11.5. The chemosensor also shows excellent performance in natural water samples.