The facile synthesis of nitrogen and sulfur co-doped carbon dots for developing a powerful "on-off-on" fluorescence probe to detect glutathione in vegetables. (15th March 2022)

• Record Type: Journal Article
• Authors: Sun, Xinyang; Wang, Chao; Li, Peng; Shao, Zhiying; Xia, Ji; Liu, Qin; Shen, Fei; Fang, Yong
• Is Part Of: Food chemistry. Volume 372(2022)
• Publication Date: 2022-03-15
• Subjects: N, S co-doped carbon dots -- "On-off-on" probe -- Glutathione -- Vegetables; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2021.131142
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Glutathione (GSH) in vegetables was tested by an "on-off-on" N, S-CDs probe. N, S-CDs' fluorescence was quenched by adding Cu 2+ of 20–200 μmol/L. N, S-CDs@Cu 2+ 's fluorescence was recovered by adding GSH of 10–150 μmol/L. GSH level measured by N, S-CDs@Cu 2+ and traditional method was consistent. N, S-CDs@Cu 2+ is a powerful fluorescent probe for GSH quantification. Abstract: To determine the glutathione (GSH) content in vegetables, an "on-off-on" fluorescence probe was developed by a synthesis of nitrogen and sulfur co-doped carbon dots (N, S-CDs) using the microwave pyrolysis considering citric acid and L-cysteine as precursors. The fluorescence of N, S-CDs was quenched by adding Cu 2+ at a concentration of 20–200 μmol/L due to the inner filter effect. The quenched fluorescence of N, S-CDs@Cu 2+ system was recovered by adding the GSH at a concentration of 10–150 μmol/L due to the sulfhydryl-metal compound mechanism. By observing the GSH concentrations measured by our N, S-CDs@Cu 2+ system vs. a traditional fluorescent chelating method, the two measurements provided the GSH data with a good consistence by showing the RSD range of 1.86%–2.27%. This indicates the validation and novelty of our N, S-CDs@Cu 2+ system as being a powerful fluorescent probe for effectively and efficiently determining the GSH in vegetables.