Electrocatalytic Mechanism for Improving Sensitivity and Specificity of Electrochemical Nucleic Acid-Based Sensors with Covalent Redox Tags-Part I.
Electrocatalytic Mechanism for Improving Sensitivity and Specificity of Electrochemical Nucleic Acid-Based Sensors with Covalent Redox Tags-Part I.
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DOI：
10.1021/acssensors.0c02362
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发表时间：
2020-12
期刊：
影响因子：
8.9
通讯作者：
Yao Wu;Sufyaan Ali;Ryan J. White
中科院分区：
文献类型：
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作者：
Yao Wu;Sufyaan Ali;Ryan J. White
为了实现高效的能量转换和电化学生物传感，人们对先进电催化的设计和开发进行了广泛的探索。铁氰化物（Fe(CN)63-）和亚甲基蓝（MB）已广泛应用于电化学生物传感策略的开发。然而，核酸拴链MB与Fe(CN)63-之间的电催化机制仍未明确。在这篇文章中，我们的目标是为我们社区的读者提供关于电催化机制的分子见解。电催化机理的探索从一个单电子均相电催化反应的动力学带图开始。过量因子γ和动力学参数λ是均相电催化反应的重要因素；因此，我们两者都学过。通过施加不同浓度（50、100和200 μM）的Fe(CN)63-来控制过量因子参数，并通过循环伏安法（CV）扫描速率和方波伏安法（SWV）频率来考察动力学参数对电催化过程的影响。此外，我们发现探针动力学的核酸系是电催化反应的第三个限速因素。由于电极结合核酸的探针动力学开关在电化学核酸传感器中经常被用作一种机制，我们认为核酸系链MB与Fe(CN)63-之间的电催化作用能够提高带有共价氧化还原标签的电化学核酸传感器的灵敏度和特异性。
The design and development of advanced electrocatalysis have been extensively explored for efficient energy conversion and electrochemical biosensing. Both ferricyanide (Fe(CN)63-) and methylene blue (MB) have been widely used in the development of electrochemical biosensing strategies. However, the electrocatalytic mechanism between nucleic acid-tethered MB and Fe(CN)63- remains unexplored. In this manuscript, we aim to provide readers in our community molecular insights into the electrocatalytic mechanism. The exploration of the electrocatalytic mechanism starts with a kinetic zone diagram for a one-electron homogeneous electrocatalytic reaction. Two factors-the excess factor γ and the kinetic parameter λ-are important for a homogeneous electrocatalytic reaction; as such, we studied both. The excess factor parameter was controlled by applying Fe(CN)63- with various concentrations (50, 100, and 200 μM), and the kinetic parameter effect on the electrocatalytic process was examined by varying scan rates of cyclic voltammetry (CV) or frequencies of square-wave voltammetry (SWV). Moreover, we discovered that the probe dynamics of the nucleic acid tether is the third rate-limiting factor for the electrocatalytic reaction. As the probe dynamics switch of electrode-bound nucleic acid is often utilized as a mechanism in electrochemical nucleic acid-based sensors, we believe the electrocatalysis between nucleic acid-tethered MB and Fe(CN)63- is capable of enhancing sensitivity and specificity of electrochemical nucleic acid-based sensors with covalent redox tags.