Highly stable N-doped carbon dots as the sensitive probe for the detection of Fe3+

The nitrogen-doped carbon dots (NCDs) are facilely fabricated by a one-step hydrothermal strategy using citric acid and o-phenylenediamine as start ingredient. The as-synthesized NCDs with a high quantum yield of 38.63% at 370 nm excitation maintain significant fluorescence stability in various complex environments, indicating that NCDs have the possibility of application in harsh environments. Moreover, after adding the Fe3+ to this as-synthesized NCDs, the emission intensity at 446 nm is remarkably reduced and exhibits line-dependent relationship in the range of 0.5–90 μM with a detection limit of 0.37 μM. Meanwhile, the fluorescence lifetime and absorption characteristics are compared respectively, and Stern−Volmer is calculated. These results illustrate that the quenched fluorescence is attributed to the synergistic effect of internal filtration effect (IFE) and static quenching. Moreover, this carbon-based sensing material has elevated efficiency in detecting Fe3+ in practical samples, implying that the sensing probe provides a fast and accurate new technique for the detection of Fe3+.