Redox Cycling in Individually Encapsulated Attoliter-Volume Nanopores
Redox Cycling in Individually Encapsulated Attoliter-Volume Nanopores
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DOI：
10.1021/acsnano.8b08693
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发表时间：
2018-12-01
期刊：
影响因子：
17.1
通讯作者：
Bohn, Paul W.
中科院分区：
文献类型：
--
作者：
Kwon, Seung-Ryong;Fu, Kaiyu;Bohn, Paul W.
氧化还原循环电化学在单独封装的阿升体积（V类似于10 aL）的纳米孔阵列的研究和报告。这些纳米孔电极阵列（NEA）结构表现出独特的电化学行为中没有观察到开放NEA，这使得纳米孔内部和本体溶液之间的氧化还原对的自由扩散。受限的纳米孔环境，通过密封NEAs与聚（二甲基硅氧烷）层，其特征在于增强的电流高达250倍，与开放NEAs相比，由于有效地捕获的氧化还原对内的纳米孔和增强的质量传输效应。此外，电化学整流（ca. 1.5-6.3），并归因于离子迁移。进行了电子元模拟来表征与纳米孔内的盘电极、水介质和环电极相关联的浓度和电势梯度，并且结果与实验观察一致。在这些自限制的阿升体积纳米孔中产生的额外的信号增强和基于氧化还原循环的整流行为在设计超灵敏传感器和基于分子的离子电子器件中是潜在有用的。
Redox cycling electrochemistry in arrays of individually encapsulated attoliter-volume (V similar to 10 aL) nanopores is investigated and reported here. These nanopore electrode array (NEA) structures exhibit distinctive electrochemical behaviors not observed in open NEAs, which allow free diffusion of redox couples between the nanopore interior and bulk solution. Confined nanopore environments, generated by sealing NEAs with a layer of poly(dimethylsiloxane), are characterized by enhanced currents-up to 250-fold compared with open NEAs-owing to effective trapping of the redox couple inside the nanopores and to enhanced mass transport effects. In addition, electrochemical rectification (ca. 1.5-6.3) was observed and is attributed to ion migration. Finite-element simulations were performed to characterize the concentration and electric potential gradients associated with the disk electrode, aqueous medium, and ring electrode inside the nanopores, and the results are consistent with experimental observations. The additional signal enhancement and redox-cycling-based rectification behaviors produced in these self-confined attoliter-volume nanopores are potentially useful in devising ultrasensitive sensors and molecular-based iontronic devices.