Boron, nitrogen, and sulfur co‐doped carbon dots as a fluorescence probe for label‐free analysis of Hg2+

Abstract Hg 2+ is one of the most toxic heavy metals, posing a serious threat to the human body and the environmental ecosystem. In order to detect Hg 2+ rapidly, accurately, and sensitively, a kind of boron, nitrogen, and sulfur co‐doped carbon dots (B,N,S‐CDs) were synthesized by a simple, economical, and direct hydrothermal method. The average size of the prepared B,N,S‐CDs is 2.7 ± 0.7 nm, and the high photoluminescence quantum yield is 67.6%. Furthermore, due to the efficient quenching effect of Hg 2+ , such B,N,S‐CDs are considered to serve as an efficient fluorescence sensing platform for label‐free and sensitive detection of Hg 2+ with a detection limit of 72 nM. The selectivity experiments reveal that the B,N,S‐CDs are selective and specific for Hg 2+ even in the presence of other interfering substances. Most importantly, the Hg 2+ sensing platform based on B,N,S‐CDs can be successfully applied to the determination of Hg 2+ in tap water and real lake water samples. This stable and inexpensive carbon material exhibits excellent sensitivity and selectivity, potentially suitable for Hg 2+ monitoring in environmental applications.