Fluorescence Coupling for Direct Imaging of Electrocatalytic Heterogeneity
Fluorescence Coupling for Direct Imaging of Electrocatalytic Heterogeneity
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DOI：
10.1021/ja310401b
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发表时间：
2013-01-16
影响因子：
15
通讯作者：
Zhang, Bo
中科院分区：
文献类型：
--
作者：
Guerrette, Joshua P.;Percival, Stephen J.;Zhang, Bo
在这里，我们报告使用荧光显微镜和封闭双极电极来揭示大型电化学阵列上的电化学和电催化活性。我们展示了荧光电化学显微镜（FEEM）作为一种新的电化学方法，用于对瞬态和异质电化学过程进行成像。该方法使用双极电极机制将传统的氧化反应（例如二茂铁的氧化）直接耦合到特殊的荧光还原反应。阴极上荧光产物的产生使得人们能够用光学显微镜直接监测电化学过程。我们演示了该方法在包含数千个或更多平行双极微电极的大型电化学阵列上的使用，以实现空间和时间分辨的电化学成像。我们首先使用包含大约 1000 个碳纤维超微电极的阵列对溶液中氧化还原分析物的分子传输进行成像。然后，我们进行了一个简单的电催化实验，以展示 FEEM 如何用于电催化剂筛选。这种新方法可用于对瞬态电化学事件进行成像，例如单个神经元和神经元网络上的快速胞吐作用事件，以及对新型电催化剂的并行、高通量筛选。
Here we report the use of fluorescence microscopy and closed bipolar electrodes to reveal electrochemical and electrocatalytic activity on large electrochemical arrays. We demonstrate fluorescence-enabled electrochemical microscopy (FEEM) as a new electrochemical approach for imaging transient and heterogeneous electrochemical processes. This method uses a bipolar electrode mechanism to directly couple a conventional oxidation reaction, e.g., the oxidation of ferrocene, to a special fluorogenic reduction reaction. The generation of the fluorescent product on the cathodic pole enables one to directly monitor an electrochemical process with optical microscopy. We demonstrate the use of this method on a large electrochemical array containing thousands or more parallel bipolar rnicroelectrodes to enable spatially and temporally resolved electrochemical imaging. We first image molecular transport of a redox analyte in solution using an array containing roughly 1000 carbon fiber ultramicroelectrodes. We then carry out a simple electrocatalysis experiment to show how FEEM can be used for electrocatalyst screening. This new method could prove useful for imaging transient electrochemical events, such as fast exocytosis events on single and networks of neurons, and for parallel, high-throughput screening of new electrocatalysts.