RNA Aptamer-Based Electrochemical Biosensor for Selective and Label-Free Analysis of Dopamine
RNA Aptamer-Based Electrochemical Biosensor for Selective and Label-Free Analysis of Dopamine
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DOI：
10.1021/ac302134s
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发表时间：
2013-01-01
影响因子：
7.4
通讯作者：
Ferapontova, Elena E.
中科院分区：
文献类型：
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作者：
Farjami, Elaheh;Campos, Rui;Ferapontova, Elena E.
多巴胺固有的氧化还原活性使其能够直接在体内进行电化学分析(Venton, b.j.; Wightman, m.r.。化学，2003,75,414A)。然而，多巴胺分析由于大脑中存在的其他电化学活性内源性化合物的干扰而变得复杂，包括多巴胺前体和代谢物以及其他神经递质（NT）。在此，我们报道了一种基于电化学RNA适体的生物传感器，用于在其他NT存在下分析多巴胺。该生物传感器利用RNA适体与多巴胺的特异性结合，固定在半胱氨酸修饰的Au电极上，并进一步电化学氧化多巴胺。在儿茶酚、肾上腺素、去甲肾上腺素、3,4-二羟基苯丙氨酸（L-DOPA）、3,4-二羟基苯乙酸（DOPAC）、甲基多巴胺和酪胺竞争浓度的条件下，适体对多巴胺的特异性识别允许在生理相关的100 nM至5 μ M范围内选择性安培检测多巴胺，这些信号在实验条件下（0.185 V /Ag /AgCl电分析）可以忽略。抗坏血酸和尿酸的干扰通过应用钠离子涂膜消除。拟合传感器响应时间为
The inherent redox activity of dopamine enables its direct electrochemical in vivo analysis (Venton, B. J.; Wightman, M. R. Anal. Chem. 2003, 75, 414A). However, dopamine analysis is complicated by the interference from other electrochemically active endogenous compounds present in the brain, including dopamine precursors and metabolites and other neurotransmitters (NT). Here we report an electrochemical RNA aptamer-based biosensor for analysis of dopamine in the presence of other NT. The biosensor exploits a specific binding of dopamine by the RNA aptamer, immobilized at a cysteamine-modified Au electrode, and further electrochemical oxidation of dopamine. Specific recognition of dopamine by the aptamer allowed a selective amperometric detection of dopamine within the physiologically relevant 100 nM to 5 mu M range in the presence of competitive concentrations of catechol, epinephrine, norepinephrine, 3,4-dihydroxy-phenylalanine (L-DOPA), 3,4-dihydroxyphenylacetic acid (DOPAC), methyldopamine, and tyramine, which gave negligible signals under conditions of experiments (electroanalysis at 0.185 V vs Ag/AgCl). The interference from ascorbic and uric acids was eliminated by application of a Nafion-coated membrane. The aptasensor response time was