A new turn-off fluorescence probe based on graphene quantum dots for detection of Au(III) ion

•Two kinds of graphene quantum dots were prepared using glucose and citric acid.•The interaction of both GQDs with several metal ions was investigated.•Au(III) ions selectively quench the fluorescence of both GQDs.•Glucose-derived GQDs show better analytical performance for Au(III) determination.

In this work, a new turn-off fluorescence probe based on the graphene quantum dots (GQDs) was designed for detection and quantification of Au(III) ion. GQDs were prepared by two simple carbonization methods using glucose (g-GQDs) and citric acid (c-GQDs) as carbon sources. The effect of some metal ions on the fluorescence intensity of the prepared GQDs was studied. It was found that the fluorescence of both GQDs is significantly quenched by Au(III) ions but the sensitivity and analytical performances are different for two prepared GQDs. Using g-GQDs, a new analytical method was developed for the determination of Au(III) in the concentration range of 1.0–80 μM, with a detection limit of 0.5 μM. The developed method was applied to the determination of Au(III) in water and plasma samples with satisfactory results.

Graphical abstractGlucose-derived GQDs are selectively quenched by Au(III) ions, which form a basis for detection and quantification of Au(III).Figure optionsDownload full-size imageDownload as PowerPoint slide