Pollution of toxic heavy-metal ions such as mercury ions (Hg2+) is well known to severely threaten ecological environment and human health. Correspondingly, development of a fast and sensitive method for detecting heavy-metal ions is urgently needed and has been received widespread attention in recent years. In this study, carbon nanodots (CDs) with strong blue fluorescence were synthesized by a microwave-assisted hydrothermal method. The as-prepared blue fluorescent CDs not only have excellent stability (e.g. photostability, salt stability and pH stability), but also have extremely high selectivity and sensitivity for probing Hg2+ via fluorescence quenching. Specifically, fluorescence of CDs is gradually quenched along with the increase in Hg2+ concentration, and a low concentration of Hg2+ can be identified (with low detection limit, 15 nM). Therefore, the novel fluorescent CDs could be developed for detecting Hg2+ in aqueous conditions, and have great potential for fast probing Hg2+ in environmental samples.
Keywords: Environmental waters; Fluorescent carbon nanodots; Mercury ions; Nanosensor; Selective detection.