Redox cycling in nanoporous electrochemical devices
Redox cycling in nanoporous electrochemical devices
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DOI：
10.1039/c3nr03818a
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发表时间：
2014-01-01
期刊：
影响因子：
6.7
通讯作者：
Wolfrum, Bernhard
中科院分区：
文献类型：
--
作者：
Hueske, Martin;Stockmann, Regina;Wolfrum, Bernhard
纳米级氧化还原循环是一种基于快速重复氧化和还原反应的检测电化学活性分子的强大技术。氧化还原循环传感器的理想实现可以通过易于访问且可扩展的几何形状的纳米多孔双电极系统来实现。在这里，我们介绍了一种具有高效纳米多孔氧化还原循环传感器的多电极阵列装置。每个传感器拥有多达 209 000 个明确的纳米孔，最小孔径小于 40 nm，电极间距接近 100 nm。我们通过筛选超过三个数量级的大浓度范围以及高达 81.0 mA (cm(-2) mM(-1)) 的氧化还原活性探针二茂铁二甲醇的区域特异性灵敏度来证明纳米孔阵列的效率。此外，由于材料的特定几何形状，反应动力学对信号特性具有独特的电势依赖性影响。因此，纳米多孔结构中的氧化还原循环实验允许对异质电子转移反应进行研究，揭示出令人惊讶的不对称转移系数。
Nanoscale redox cycling is a powerful technique for detecting electrochemically active molecules, based on fast repetitive oxidation and reduction reactions. An ideal implementation of redox cycling sensors can be realized by nanoporous dual-electrode systems in easily accessible and scalable geometries. Here, we introduce a multi-electrode array device with highly efficient nanoporous redox cycling sensors. Each of the sensors holds up to 209 000 well defined nanopores with minimal pore radii of less than 40 nm and an electrode separation of similar to 100 nm. We demonstrate the efficiency of the nanopore array by screening a large concentration range over three orders of magnitude with area-specific sensitivities of up to 81.0 mA (cm(-2) mM(-1)) for the redox-active probe ferrocene dimethanol. Furthermore, due to the specific geometry of the material, reaction kinetics has a unique potential-dependent impact on the signal characteristics. As a result, redox cycling experiments in the nanoporous structure allow studies on heterogeneous electron transfer reactions revealing a surprisingly asymmetric transfer coefficient.