Nitrogen-doped graphene quantum dots as highly sensitive and selective fluorescence sensor detection of iodide ions in milk powder

作者：Zhang, Bingyan; He, Yanhua; Fan, Zhefeng^*

来源：Journal of Photochemistry and Photobiology A: Chemistry , 2018, 367: 452-457.

DOI：10.1016/j.jphotochem.2018.09.014

• N-GQDs
• Fluorescent sensor
• Silver ions
• Iodide ions

In this work, we have successfully designed an "off-on" fluorescent sensor based on nitrogen-doped graphene quantum dots (N-GQDs) system to detect iodide ions in milk powder. The fluorescence intensity of N-GQDs was significantly quenched by Ag+ through forming N-GQDs/Ag+ complexes due to the binding between Ag+ and functional groups on the surface of N-GQDs. However, with the addition of I- to the N-GQDs/Ag+ system, the fluorescence intensity was significantly restored because of the formation of AgI complexes by "hard and soft acids and bases principle"(HSAB) between Ag+ and I-. Under the optimal conditions, Ag+ had a good linear relationship in the range of 0.01-0.6 mu M. The fluorescence intensity of N-GQDs/Ag+ linearly increased with the increasing of I- concentrations in the range of 0.0125-4.0 mu M, and the detection limit (LOD) was 5.6 nM. The proposed method has been successfully applied to the detection of milk powder, which is a detection system with good development prospects owing to convenience, rapidity and low toxicity.

• 出版日期2018-12-1
• 单位山西师范大学