N, S co‑doped fluorescent carbon dots synthesized by microwave irradiation: a sensitive probe for Pb (II) ions detection in food samples

다국어 초록 (Multilingual Abstract)

Sulfur and nitrogen co-doped carbon dots (NSCDs) were quickly synthesized by the microwave-assisted method from triammonium citrate and thiourea. NSCDs showed a quantum yield of 11.5% with excitation and emission bands at 355 and 432 nm, respectively. Also, a fluorescence quenching was observed in the presence of Pb(II) ions, and the as-synthesized CDs were used as a sensitive probe for detecting Pb(II) in water and food samples. The results showed the optimal conditions for Pb(II) determination were CDs concentration of 0.02 mg mL? 1 at pH 6.0–7.0 and an incubation time of 20 min. The relative fluorescence intensity of NSCDs was proportional to Pb(II) concentrations in the range of 0.029–2.40 and 2.40–14.4 μmol L? 1 with a correlation coefficient (R2) of 0.998 and 0.955, respectively, and a detection limit of 9.2 × 10– 3 μmol L? 1. Responses were highly repeatable, with a standard deviation below 3.5%. The suggested method demonstrates the potential of a green, fast, and low-cost approach for Pb(II) determination in water, tea, and rice samples with satisfying results.

목차 (Table of Contents)

• N, S co-doped fluorescent carbon dots synthesized by?microwave irradiation: a?sensitive probe for?Pb (II) ions detection in?food samples
• Abstract
• 1 Introduction
• 2 Materials and?methods
• 2.1 Instrumentation
• 2.2 Chemicals and?reagents
• 2.3 Preparation of?carbon dots
• 2.4 Quantum yield calculation
• 2.5 Fluorescence measurement of?Pb(II) ions
• 2.6 Effects of?coexisting ions
• 2.7 Treatment of?real samples
• 3 Results and?discussion
• 3.1 Synthesis and?characterization of?CDs
• 3.2 Fluorogenic detection of?Pb(II)
• 3.3 Analytical features
• 3.4 Interference study
• 3.5 Analysis of?food samples
• 4 Conclusion
• Anchor 19
• Acknowledgements
• References