Use of Electrocatalysis for Differentiating DNA Polymorphisms and Enhancing the Sensitivity of Electrochemical Nucleic Acid-Based Sensors with Covalent Redox Tags-Part II.
Use of Electrocatalysis for Differentiating DNA Polymorphisms and Enhancing the Sensitivity of Electrochemical Nucleic Acid-Based Sensors with Covalent Redox Tags-Part II.
复制标题
使用电催化区分 DNA 多态性并增强带有共价氧化还原标签的电化学核酸传感器的灵敏度 - 第二部分。
DOI：
10.1021/acssensors.0c02363
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发表时间：
2020
期刊：
影响因子：
8.9
通讯作者：
White,RyanJ
中科院分区：
文献类型：
--
作者：
Wu,Yao;Ali,Sufyaan;White,RyanJ
单核苷酸多态性 (SNP)、插入/缺失 (indel) 多态性和 DNA 甲基化是最常见的遗传变异类型。因此，DNA 多态性在遗传图谱和诊断中发挥着重要作用。因此，能够检测 DNA 多态性的分析方法将为早期疾病诊断提供宝贵的手段。然而，还没有一种基于核酸的电化学传感器能够以足够的特异性和灵敏度实现对三种主要多态性（SNP、插入缺失多态性和DNA甲基化）的检测。为此，我们探索利用与表面结合的核酸共价连接的亚甲基蓝 (MB) 和自由扩散的铁氰化物 (Fe(CN)63–) 之间的催化反应来提高 DNA 多态性检测的特异性和灵敏度。我们发现，除了更传统的动力学和过量因素之外，核酸系链的动力学是电催化反应的另一个限速因素。我们的概念验证实验表明，当目标序列浓度为 10 nM 时，使用电催化可以区分三种多态性。我们假设这种能力是 DNA 探针具有各自多态性的独特动力学的结果。除了传感器显示的特异性外，传感器还实现了 20 pM 的检测限。我们相信，核酸束缚的 MB 和 Fe(CN)63 之间的电催化对于基于电化学核酸的传感器来说非常有希望实现更好的特异性和灵敏度。
Single-nucleotide polymorphisms (SNPs), insertion/deletion (indel) polymorphisms, and DNA methylation are the most frequent types of genetic variations. As such, DNA polymorphisms play significant roles in genetic mapping and diagnostics. Thus, analytical methods enabling DNA polymorphism detection will provide an invaluable means for early disease diagnosis. However, no single electrochemical nucleic acid-based sensor has achieved the detection of the three major polymorphisms (SNPs, indel polymorphisms, and DNA methylation) with sufficient specificity and sensitivity. In response, we explore the utilization of a catalytic reaction between methylene blue (MB) covalently linked to surface-bound nucleic acid and freely diffusing ferricyanide (Fe(CN)63–) to improve specificity and sensitivity of DNA polymorphism detection. We find that the dynamics of the nucleic acid tether is an additional rate-limiting factor for the electrocatalytic reaction, in addition to the more traditional kinetic and excess factors. Our proof-of-concept experiments demonstrate that the use of electrocatalysis enables differentiation of the three polymorphisms when target sequences are present at 10 nM. We hypothesize that this ability is a result of the distinct dynamics of the DNA probe with each respective polymorphism. In addition to the specificity the sensor displays, the sensor achieves a 20 pM limit of detection. We believe that the electrocatalysis between nucleic acid-tethered MB and Fe(CN)63–is highly promising for electrochemical nucleic acid-based sensors to achieve better specificity and sensitivity.