One-step preparation of single-layered graphene quantum dots for the detection of Fe3+

Single-layer graphene quantum dots are highly desirable while their facile and controllable preparations remain challenging. Herein, single-layered graphene quantum dots (sl-GQDs) were developed via a facile one-step hydrothermal synthesis, with citric acid and β-cyclodextrin (CD) as starting materials. The sl-GQDs decorated with CD molecules emit green fluorescence with a quantum yield of 5.34%, and exhibit a good response exclusively to ferric ions for their structural oxygenous groups. The linear range of the proposed sensor for ferric ions was found in a wide concentration range of 0–85 μM. The detection limit is about 0.26 μM. The sl-GQDs based sensing platform also demonstrates its feasibility in real water sample analysis with recoveries of 93.8%–101.5%.