Aptamer-based electrochemical sensors with aptamer-complementary DNA oligonucleotides as probe
Aptamer-based electrochemical sensors with aptamer-complementary DNA oligonucleotides as probe
复制标题
以适配体互补 DNA 寡核苷酸作为探针的基于适配体的电化学传感器
DOI：
10.1021/ac7018014
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发表时间：
2008-03-15
影响因子：
7.4
通讯作者：
Mao, Lanqun
中科院分区：
文献类型：
--
作者：
Lu, Ying;Li, Xianchan;Mao, Lanqun
本研究描述了一个简单的和一般的策略，用于开发基于适体的电化学传感器，该传感器具有对目标的高度特异性和容易再生的功能。与现有的以适体为探针开发电化学适体传感器的策略非常不同，本文提出的策略基本上是基于利用适体互补DNA（cDNA）寡核苷酸作为电化学传感的探针。在这种情况下，cDNA两端的序列被定制为互补的，并且氧化还原部分（即，二茂铁）和巯基标记到cDNA上。标记的cDNA与它们各自的适体杂交（即，ATP-和凝血酶-结合的适配体）形成双链DNA（dsDNA），并通过将标记的ds-DNA自组装到Au电极上来制备电化学适配器。在靶结合时，限制在电极表面上的适体从其各自的cDNA寡核苷酸解离到溶液中，并且单链cDNA因此可以倾向于通过其两端的互补序列的杂交形成发夹结构。如此的构象。由靶结合诱导的适体解离引起的cDNA的变化基本上导致标记在cDNA上的氧化还原部分的伏安信号的变化，因此构成了电化学适体传感器用于特异性靶传感的机制。这里用cDNA作为探针证明的适体传感器很容易再生，并对靶标显示出良好的响应。本研究为电化学适体传感器的研究提供了一种新的、相对通用的方法，具有良好的分析性能和潜在的应用价值。
This study describes a facile and general strategy for the development of aptamer-based electrochemical sensors with a high specificity toward the targets and a ready regeneration feature. Very different from the existing strategies for the development of electrochemical aptasensors with the aptamers as the probes, the strategy proposed here is essentially based on the utilization of the aptamer-complementary DNA (cDNA) oligonucleotides as the probes for electrochemical sensing. In this context, the sequences at both ends of the cDNA are tailor-made to be complementary and both the redox moiety (i.e., ferrocene in this study) and thiol group are labeled onto the cDNA. The labeled cDNA are hybridized with their respective aptamers (i.e., ATP- and thrombin-binding aptamers in this study) to form double-stranded DNA (dsDNA) and the electrochemical aptasensors are prepared by self-assembling the labeled ds-DNA onto Au electrodes. Upon target binding, the aptamers confined onto electrode surface dissociate from their respective cDNA oligonucleotides into the solution and the single-stranded cDNA could thus tend to form a hairpin structure through the hybridization of the complementary sequences at both its ends. Such a conformational. change of the cDNA resulting from the target binding-induced dissociation of the aptamers essentially leads to the change in the voltammetric signal of the redox moiety labeled onto the cDNA and thus constitutes the mechanism for the electrochemical aptasensors for specific target sensing. The aptasensors demonstrated here with the cDNA as the probe are readily regenerated and show good responses toward the targets. This study may offer a new and relatively general approach to electrochemical aptasensors with good analytical properties and potential applications.