A highly selective and sensitive "on-off" fluorescent probe for detecting cadmium ions and l-cysteine based on nitrogen and boron co-doped carbon quantum dots

Authors：Yan, Zhihong; Yao, Wei; Mai, Kang; Huang, Jiaqi; Wan, Yating; Huang, Liu^*; Cai, Bo^*; Liu, Yi^*

Source：2022, 12(13): 8202-8210.

DOI：10.1039/d1ra08219a

• LARGE-SCALE SYNTHESIS
• MERCURY IONS
• CITRIC-ACID
• II IONS
• NANODOTS
• SENSOR
• PHOTOLUMINESCENCE
• GLUTATHIONE
• ZINC
• CD2+

Cadmium ions (Cd2+) have caused relatively serious pollution, threatening human health and ecosystems. l-Cysteine (l-Cys) is an essential amino acid in living organisms and concentration of l-Cys is closely related to some human diseases. In this work, we first introduced 2-amino-3-hydroxypyridine and sodium borohydride as the nitrogen source and boron source to fabricate boron and nitrogen co-doped carbon quantum dots (N,B-CQDs) with high fluorescence quantum yield (21.2%), which were synthesized through a simple, low-consumption and pollution-free one-pot hydrothermal method. The obtained N,B-CQDs are able to detect Cd2+ rapidly and sensitively through fluorescence enhancement, which may be ascribed to chelation enhanced fluorescence that is induced by the formation of the N,B-CQDs/Cd2+ complex. Simultaneously, N,B-CQDs can be used to detect l-cysteine because significant fluorescence quenching was observed when l-Cys was added into the N,B-CQDs/Cd2+ system. In the two fluorescence "turn-on" and "turn-off" processes, this fluorescent probe obtained a good linear relationship over Cd2+ concentration ranging from 2.5 mu M to 22.5 mu M with a detection limit of 0.45 mu M, while the concentration of l-cysteine showed a linear relationship in the range of 2.5-17.5 mu M with a detection limit of 0.28 mu M. The sensor has been successfully used to detect Cd2+ and l-cysteine in real samples with satisfying results.

• Institution
  广东药学院; y