Detection, detoxification, and removal of multiply heavy metal ions using a recyclable probe enabled by click and declick chemistry

The pollution of water with heavy metal ions has generated great concern among both the public and academics due to the high toxicity, persistence, and non-degradability of heavy metals. The detection, detoxification, and removal of heavy metal ions are critical for monitoring water quality and treating polluted water. However, these tasks remain challenging due to lack of effective detection, detoxification, and removal strategies. By combining thiol-triggered click chemistry and heavy metal ion-triggered declick chemistry, a recyclable fluorescent probe for detecting numerous heavy metal ions was successfully developed through simple addition of thiol-containing heavy metal antidote to a carefully selected Michael acceptor-type fluorophore. The probe could be regenerated by adding equal amount of antidote to the detection solution without any purification step recycled up to 10 times. The generated water-soluble heavy metal ion-antidote complexes showed weak toxicity to biological systems, indicating successful detoxification. Finally, a simple, economical, and practical device for detecting, detoxifying, and removing heavy metal ions was fabricated by loading the recyclable fluorescent probe into polymer beads. The percent of detection, and removal are 98.10% and 97.59%, respectively. And detoxification percent is as high as 65.55%. The device is a promising candidate for water quality monitoring and treatment.