A simple microwave-assisted synthesis of nitrogen-doped carbon dots with high oxygen content (O-N-CDs) was carried out with citric acid as a carbon source and 2,4-diamino-6-methyl-1,3,5-triazine as a nitrogen source in triethylene glycol (TEG) media. It was determined by SEM analysis that O-N-CDs consisted of particles of different sizes and shapes. Transmission electron microscopy (TEM), Raman spectroscopy, and X-ray diffraction (XRD) analysis confirmed that O-N-CDs have a graphitic structure. Moreover, they showed a high fluorescence property based on the excitation wavelength. Therefore, a new fluorometric method was developed for the determination of banned food dye Sudan II by using the O-N-CDs. The proposed method was used in the determination of Sudan II in spiked spice samples. The detection limit was 0.6 mg L⁻¹ and the linear range was 0–8 mg L⁻¹.

以柠檬酸为碳源，2,4-二氨基-6-甲基-1,3,5-三嗪为碳源，采用微波辅助合成高氧含量氮掺杂碳点 (ON-CDs)。三甘醇 (TEG) 介质中的氮源。通过SEM分析确定ON-CD由不同大小和形状的颗粒组成。透射电子显微镜 (TEM)、拉曼光谱和 X 射线衍射 (XRD) 分析证实 ON-CD 具有石墨结构。此外，它们显示出基于激发波长的高荧光特性。因此，开发了一种使用 ON-CD 测定禁用食品染料 Sudan II 的新荧光法。所提出的方法用于测定加标香料样品中的苏丹红 II。检出限为 0.6 mg L ^-1线性范围为0–8 mg L ⁻¹。