Electrochemiluminescence Self-Interference Spectroscopy with Vertical Nanoscale Resolution
Electrochemiluminescence Self-Interference Spectroscopy with Vertical Nanoscale Resolution
复制标题
具有垂直纳米级分辨率的电化学发光自干涉光谱
DOI：
10.1021/jacs.9b12833
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发表时间：
2020-01-22
影响因子：
15
通讯作者：
Su, Bin
中科院分区：
文献类型：
--
作者：
Wang, Yafeng;Guo, Weiliang;Su, Bin
在这里，我们报告了电化学发光（ECL）的自干涉光谱技术（指定为ECLIS）的空间分辨率在电极表面的法线方向。自干涉主要来源于由发光体直接发射的ECL和从电极表面反射的ECL的叠加，导致由有序分布的峰组成的光谱。在此基础上，通过矩阵传播模型的光谱和理论分析，发光体和电极表面之间的距离可以探测与纳米尺度上的垂直分辨率。在这项工作中，我们首先证明了使用不同的分子连接体（如双链DNA）组装在电极表面上的ECL发光体的高度，以及连接体分子在表面上的可能构象。此外，ECL发射层的厚度邻近电极表面的经典共反应物ECL系统包括自由扩散的Ru（bpy）（3）（2+）和三正丙胺在溶液中估计。根据Ru（bpy）（3）（2+）的浓度不同，其厚度从350 nm到1 μ m不等。我们相信，具有高的垂直分辨率的ECLIS将提供一个简单的方法来收集分子构象信息和研究电化学发光反应机制在电极界面。
Here we report an electrochemiluminescence (ECL) self-interference spectroscopy technique (designated as ECLIS) with spatial resolution in the normal direction of the electrode surface. Self-interference principally originates from the superposition of ECL emitted directly by luminophores and that reflected from electrode surfaces, resulting in a spectrum consisting of orderly distributed peaks. On the basis of this spectrum and theoretical analysis by the matrix propagation model, the distance between luminophores and the electrode surface can be probed with a vertical resolution on the nanometer scale. We demonstrated first in this work that the height of ECL luminophores assembled on the electrode surface using different molecular linkers, such as double-stranded DNA, could be determined, as well as the possible conformation of linker molecules at the surface. Moreover, the thickness of the ECL emitting layer adjacent to the electrode surface was estimated for the classical coreactant ECL systems involving freely diffusing Ru(bpy)(3)(2+) and tri-n-propylamine in solutions. The thickness was found to vary from similar to 350 nm to nearly 1 mu m depending on the concentration of Ru(bpy)(3)(2+). We believe that ECLIS with a high vertical resolution will provide an easy way to collect molecular conformation information and study ECL reaction mechanisms at electrode interfaces.