Hydrothermal synthesis of carbon quantum dots (CQDs) from natural biomass is a green and sustainable route for CQDs applications in various fields. In this work, the preparation and characterization of CQDs based on quinoa saponin were investigated. The optimum synthetic conditions determined by orthogonal experiments were as follows: 2 g quinoa saponin powder and 0.04 mol ethylenediamine reacted at 200°C for 10 h. The relative fluorescence quantum yield (QY = 22.2%) can be obtained, which is higher than some results reported in the literatures. The prepared CQDs had a small and uniform size (∼2.25 nm) and exhibited excitation wavelength-dependent blue light emission behavior. The CQDs displayed excellent sensitivity for Co²⁺ detection along with good linear correlation ranging from 20 to 150 µM and the detection limit of 0.49 µM. The CQDs prepared in this experiment were successfully implanted into soybean sprouts for fluorescence imaging. The sprouts could grow healthily even soaked in the CQDs solution for two weeks, demonstrating the low toxicity of the CQDs. The advantages of the CQDs, such as low cost, ease of manufacture, nontoxicity, and stability, have potential applications in many areas such as metal ion detection and biosensing.

中文翻译：

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从生物质藜麦皂苷中简便且高产地合成 N 掺杂碳量子点，用于检测 Co2+

从天然生物质中水热合成碳量子点 (CQDs) 是 CQDs 在各个领域应用的绿色可持续途径。在这项工作中，研究了基于藜麦皂苷的 CQD 的制备和表征。正交实验确定的最佳合成条件为：2 g藜麦皂苷粉与0.04 mol乙二胺在200℃反应10 h。可以获得相对荧光量子产率（QY = 22.2%），高于一些文献报道的结果。制备的 CQD 具有小而均匀的尺寸（~2.25 nm），并表现出与激发波长相关的蓝光发射行为。CQD 显示出对 Co ²⁺检测的出色灵敏度以及 20 到 150 µ范围内的良好线性相关性 M 和 0.49 µ M的检测限。 本实验制备的 CQDs 成功植入豆芽进行荧光成像。即使在 CQDs 溶液中浸泡两周，芽也可以健康生长，证明了 CQDs 的低毒性。CQDs具有成本低、易于制造、无毒、稳定等优点，在金属离子检测和生物传感等许多领域具有潜在的应用价值。