College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China.
Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China.
Int J Environ Res Public Health. 2019 Jul 14;16(14):2518. doi: 10.3390/ijerph16142518.
In this paper, nitrogen-doped carbon quantum dots (N-CQDs) were synthesized by a solvothermal method using 1,2,4-triaminobenzene as a carbon precursor. The surface of the synthesized N-CQDs was modified with amino functional groups. The results indicated that N-CQDs had various N-related functional groups and chemical bonds and were amorphous in structure. At the same time, the quantum yield of N-CQDs was 5.11%, and the average lifetime of fluorescence decay was 5.79 ns. The synthesized N-CQDs showed good selectivity for and sensitivity to Ag. A linear relationship between N-CQDs detection efficiency and Ag concentration was observed for concentration ranges of Ag corresponding to 0-10 μM and 10-30 μM. In addition, N-CQDs were used for the detection of trace Ag in food packaging material. The silver ion content of the sample determined by the N-CQDs detection method was 1.442 mg/L, with a relative error of 6.24% with respect to flame atomic absorption spectrometry, according to which the Ag content was 1.352 mg/L. This indicates that the N-CQDs detection method is reliable. Therefore, the N-CQDs prepared in this paper can detect Ag rapidly, simply, and sensitively and are expected to be a promising tool for the detection of trace Ag in food packaging materials.
在本文中，氮掺杂碳量子点（N-CQDs）是通过溶剂热法使用 1,2,4-三氨基苯作为碳前体制备的。合成的 N-CQDs 的表面用氨基官能团进行了修饰。结果表明，N-CQDs 具有各种 N 相关的官能团和化学键，并且结构无定形。同时，N-CQDs 的量子产率为 5.11%，荧光衰减的平均寿命为 5.79 ns。合成的 N-CQDs 对 Ag 表现出良好的选择性和灵敏度。对于对应于 0-10 μM 和 10-30 μM 的 Ag 浓度范围，观察到 N-CQDs 检测效率与 Ag 浓度之间的线性关系。此外，N-CQDs 用于检测食品包装材料中的痕量 Ag。用 N-CQDs 检测方法测定的样品中银离子的含量为 1.442 mg/L，相对于火焰原子吸收光谱法的相对误差为 6.24%，根据该方法，Ag 的含量为 1.352 mg/L。这表明 N-CQDs 检测方法是可靠的。因此，本文制备的 N-CQDs 可以快速、简单、灵敏地检测 Ag，有望成为检测食品包装材料中痕量 Ag 的一种有前途的工具。
