Abstract A new method was constructed for detecting dopamine based on aptamer-specific recognition and resonance Rayleigh scattering (RRS) of G - quadruplex nanowires (G - wires). The dopamine aptamer was used to recognize the target of dopamine, and the Exonuclease III was applied to cleave the hairpin DNA, and the G - wire formation was induced in the presence of K+ and Mg2+. This phenomenon was confirmed by polyacrylamide gel electrophoresis. Thus, a quantitative relationship between the RRS intensity of the G - wires and the dopamine concentration was established. The experimental conditions were optimized, such as the concentration of Mg2+, reaction temperature, reaction time and the concentration of Exonuclease III in the reaction system, and the interference substances were investigated, such as uric acid, ascorbic acid and serotonin. Under the optimal conditions, there was a good linear relationship between the RRS and the logarithm of dopamine concentration in the range from 5.0 × 10-11 M to 1.0 × 10-8 M (r = 0.995), with a detection limit of 1.2 × 10-11 M. The novel method for dopamine detection showed excellent selectivity and high sensitivity, and could be used to detect dopamine in mice brain tissues.

中文翻译：

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基于外切核酸酶 Ш 辅助信号放大的新型共振瑞利散射适体传感器用于多巴胺检测

摘要 基于G-四联体纳米线（G-线）的适配体特异性识别和共振瑞利散射（RRS），构建了一种检测多巴胺的新方法。多巴胺适体用于识别多巴胺的靶标，应用核酸外切酶III切割发夹DNA，在K+和Mg2+存在下诱导G-线形成。聚丙烯酰胺凝胶电泳证实了这一现象。因此，建立了 G 线的 RRS 强度与多巴胺浓度之间的定量关系。对反应体系中Mg2+浓度、反应温度、反应时间、核酸外切酶III浓度等实验条件进行了优化，考察了干扰物质如尿酸、抗坏血酸、血清素等。