A fluorescein-based fluorescent probe for real-time monitoring hypochlorite

Hypochlorite is an important reactive oxygen species in environment and pathophysiological processes. Abnormal level of ClO− can be destructive and lead to many diseases. Herein, to real-time and sensitively monitoring ClO−, a fluorescein-based fluorescence turn-on probe for ClO− in almost pure PBS buffer solution was successfully developed. After sensing hypochlorite, the spirolactam ring of the probe was opened and fluorescence at 525 nm greatly enhanced (∼1800 fold). The probe has a low detection limit (9.6 nM), short response time (∼1 min) and wide pH work range (5.0–9.0). Furthermore, the probe has been successfully applied to detect ClO− in disinfectant and actual water samples. Based on its fast response rate and almost pure buffer detection condition, the probe can be used to real time monitor ClO− in actual water environment.