One-step Synthesis of Highly Luminescent Nitrogen-doped Carbon Dots for Selective and Sensitive Detection of Mercury(II) Ions and Cellular Imaging

In this paper, nitrogen-doped carbon dots (N-CDs) with high quantum yield (QY) of 40.5% were prepared through a facile and straightforward hydrothermal route. The as-prepared N-CDs exhibited excellent photoluminescence properties, good water-solublity and photostability, negligible cytotoxicity and favourable biocompatibility. Such N-CDs were found to serve as an effective fluorescent sensor for selective and sensitive detection of Hg2+ in a wide linear response concentration range of 0 – 8 µM with a limit of detection (LOD) of 0.087 µM and could be applied to the determination of Hg2+ in environmental water samples. The corresponding mechanisms were discussed in detail. Moreover, another attractive finding was that the N-CDs showed satisfactory performance in bioimaging before and after the addition of Hg2+ in human lung cancer PC14 cells. With excellent sensitivity, selectivity and biocompatibility, such cheap carbonmaterials are potentially suitable for monitoring of Hg2+ in environmental applications and promising for biological applications.