Facilely synthesized N-doped carbon quantum dots with high fluorescent yield for sensing Fe3+

Nitrogen doped carbon quantum dots (NCQDs) were synthesized using L-glutamic acid as raw material through a facile, effective and green hydrothermal method in one pot. Without any chemical reagents and further surface modifications, the NCQDs emit bright blue fluorescence with a high quantum yield of 17.8% due to the fluorescence enhancement effect of N dopant atoms on a surface of carbon quantum dots. Moreover, the NCQDs present a sensitive response to Fe3+ ions with a detection limit of 4.67 mu M (S/N = 3) through the variation in fluorescence with respect to the target concentration and based on electron transfer from the NCQDs to Fe3+ ions.