Carbon dots-magnetic nanocomposites for the detection and removal of Hg.

The dual functional detection and removal of heavy ion metals by carbon dots has become an urgent matter of concern. Here, a unique fluorescent carbon dot-magnetic nanocomposite (FeO/CDs) was prepared by hydrothermal methods for sensitive detection of Hg. The FeO/CDs serve as fluorescent probes with higher selectivity and sensitivity for Hg, with the lowest detectable limit of 0.3 nM. Hg statically quenched the blue emission of FeO/CDs, which can be restored in the presence of saturated EDTA solution. The utilization of FeO/CDs was fulfilled by recovering their emission conveniently. The recovery of Hg in Chagan Lake water, tap water and drinks was calculated at 96.5 ~ 108.8%, which demonstrates the feasibility of the FeO/CDs sensing system in natural samples. Notably, the FeO/CDs can drive the effective removal of Hg from samples, which is of outstanding significance as a promising probe in environmental monitoring.