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

Abstract

Hg²⁺ is one of the most toxic heavy metals, posing a serious threat to the human body and the environmental ecosystem. In order to detect Hg²⁺ 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 Hg²⁺, such B,N,S-CDs are considered to serve as an efficient fluorescence sensing platform for label-free and sensitive detection of Hg²⁺ with a detection limit of 72 nM. The selectivity experiments reveal that the B,N,S-CDs are selective and specific for Hg²⁺ even in the presence of other interfering substances. Most importantly, the Hg²⁺ sensing platform based on B,N,S-CDs can be successfully applied to the determination of Hg²⁺ in tap water and real lake water samples. This stable and inexpensive carbon material exhibits excellent sensitivity and selectivity, potentially suitable for Hg²⁺ monitoring in environmental applications.