Bifunctional Nitrogen and Fluorine Co-Doped Carbon Dots for Selective Detection of Copper and Sulfide Ions in Real Water Samples

Abstract

Copper ions (Cu2+) and sulfur ions (S2−) are important elements widely used in industry. However, these ions have the risk of polluting the water environment. Therefore, rapid and quantitative detection methods for Cu2+ and S2− are urgently required. Using 2,4-difluorobenzoic acid and L-lysine as precursors, nitrogen and fluorine co-doped dots (N, F-CDs) were synthesized in this study via a hydrothermal method. The aqueous N, F-CDs showed excellent stability, exhibited satisfactory selectivity and excellent anti-interference ability for Cu2+ detection. The N, F-CDs, based on the redox reactions for selective and quantitative detection of Cu2+, showed a wide linear range (0–200 μM) with a detection limit (215 nM). By forming the N, F-CDs@Cu2+ sensing platform and based on the high affinity of S2− to Cu2+, the N, F-CDs@Cu2+ can specifically detect S2− over a linear range of 0–200 μM with a detection limit of 347 nM. In addition, these fluorescent probes achieved good results when used for Cu2+ and S2− detection in environmental water samples, implying the good potential for applications.

Visible-Light-Activated Carbon Dot Photocatalyst for ROS-Mediated Inhibition of Algae Growth

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Ganoderma lucidum bran-derived blue-emissive and green-emissive carbon dots for detection of copper ions

“…Ma et al 62 prepared CDs as a potential probe for metal ion sensing by a simple stirring treatment of AC with sulfuric acid, ranging from 0 to 500 μmol L −1 , the LOD was 2.40 μmol L −1 . Zeng et al 63 utilized 2,4-difluorobenzoic acid and l -lysine as precursors to synthesize nitrogen fluoride co-doped CDs by hydrothermal method. Within the concentration range of 0–200 μmol L −1 , LOD was 0.22 μmol L −1 .…”

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“…According to fluorescence spectroscopy, the N, S, and P codoped CQDs exhibited red‐shifts in both the maximum excitation and emission wavelengths as the reaction temperature increased. Zeng et al [ 136 ] created novel N and F codoped CQDs with green emission through a hydrothermal process using 2,4‐difluorobenzoic acid and l ‐lysine as precursors. The resulting N, F‐CQDs consisted of 66.3% carbon, 11.2% nitrogen, 15.5% oxygen, and 7% fluorine and exhibited a significant QY of 38.65% with green fluorescent emission suitable for ion detection.…”