One pot synthesis of highly fluorescent N doped C-dots and used as fluorescent probe detection for Hg2+ and Ag+ in aqueous solution

A kind of biocompatible fluorescent nitrogen doped carbon quantum dots (NCDs) has been synthesized using uric acid as raw material through a facile, effective and green thermal treatment method in one pot. The surface morphology and optical properties of the synthesized NCDs were characterized. Without further chemical modification, the NCDs emit bright blue fluorescence with a high quantum yield of 56% due to the enhancement effect of N dopant atoms on a surface of carbon quantum dots. Owing to the strong blue fluorescence, negligible toxicity and the special response of heavy metal ions, the NCDs have been used as a fluorescence probe for sensitive and selective detection of Hg 2+ and Ag + ions with detection limit of 4.8   nM and 1   nM, respectively. Moreover, it was successfully applied to determination of Hg 2+ and Ag + in real environmental water samples, which offers the advantages of simplicity and cost efficiency.