Abstract Although polysaccharide-based carbon quantum dots (CQDs) are widely used in the field of detection, most of the CQDs-based sensors only take advantage of their optical properties. In this work, considering the selectivity to target substance and reducibility of xylan-based CQDs, a high-sensitive sensor based on greenly synthesized CQDs-based nanocomposite was fabricated for dopamine (DA) detection. First, the CQDs prepared from xylan were used as the reductant and stabilizer to quickly synthesize silver nanoparticles (Ag NPs) and reduced graphene oxide (rGO), and then Ag@CQDs-rGO nanocomposite was obtained and loaded on glassy carbon electrode (GCE) to fabricate electrochemical sensor. The electrochemical sensing of DA is of great significance for studying and treating neurochemical diseases due to its potential feasibility in diagnostics. Under optimal conditions, the linear range for monitoring DA was from 0.1 to 300 μM with a limit of detection of 1.59 nM (S/N=3). Finally, this sensor was successfully applied to detect DA in dopamine hydrochloride injection and bovine serum solution samples. The proposed strategy may broaden the application of polysaccharide-based CQDs and this sensor may provide a discriminative and sensitive analytical platform for DA clinical diagnostics and drug screening.

中文翻译：

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基于木聚糖基Ag@CQDs-rGO纳米复合材料的高灵敏度电化学传感器用于多巴胺检测

摘要 虽然多糖基碳量子点（CQDs）在检测领域得到广泛应用，但大多数基于CQDs的传感器仅利用其光学特性。在这项工作中，考虑到目标物质的选择性和基于木聚糖的 CQDs 的还原性，基于绿色合成的 CQDs 纳米复合材料制造了一种用于多巴胺 (DA) 检测的高灵敏度传感器。首先，以木聚糖制备的 CQDs 作为还原剂和稳定剂，快速合成银纳米粒子 (Ag NPs) 和还原氧化石墨烯 (rGO)，然后获得 Ag@CQDs-rGO 纳米复合材料并负载在玻碳电极 (GCE) 上制作电化学传感器。DA 的电化学传感由于其在诊断中的潜在可行性，对研究和治疗神经化学疾病具有重要意义。在最佳条件下，监测 DA 的线性范围为 0.1 至 300 μM，检测限为 1.59 nM (S/N=3)。最后，该传感器成功应用于检测盐酸多巴胺注射液和牛血清溶液样品中的DA。所提出的策略可以拓宽基于多糖的 CQD 的应用，并且该传感器可以为 DA 临床诊断和药物筛选提供一个有辨别力和灵敏的分析平台。