Nanoplasmonic sensing of metal-halide complex formation and the electric double layer capacitor
Nanoplasmonic sensing of metal-halide complex formation and the electric double layer capacitor
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DOI：
10.1039/c2nr11950a
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发表时间：
2012-01-01
期刊：
影响因子：
6.7
通讯作者：
Voeroes, Janos
中科院分区：
文献类型：
--
作者：
Dahlin, Andreas B.;Zahn, Raphael;Voeroes, Janos
许多纳米技术设备都基于使用等离子体纳米结构实现电化学，但这些系统很难理解。我们提出了一个详细的研究电化学电位对等离子体共振的影响，在没有表面涂层和氧化还原活性分子，同步伏安法和光谱。利用改进的方法制备了金纳米盘和金薄膜中的纳米孔阵列。高分辨率光谱和可变扫描速率提供了新的见解。此外，我们引入新的分析模型，以了解光谱的变化定量。与大多数以前的文献相比，我们发现等离子体信号几乎完全是由金属表面上离子络合物的形成引起的，在本研究中最有可能是氯化金。双电层中离子的折射传感效应可以完全忽略，金属的充电对这些系统的影响小得惊人。我们的结论是一致的本地化纳米粒子等离子体和传播表面等离子体。我们认为这项工作的结果在电化学和光学传感器相结合的背景下特别重要。
Many nanotechnological devices are based on implementing electrochemistry with plasmonic nanostructures, but these systems are challenging to understand. We present a detailed study of the influence of electrochemical potentials on plasmon resonances, in the absence of surface coatings and redox active molecules, by synchronized voltammetry and spectroscopy. The experiments are performed on gold nanodisks and nanohole arrays in thin gold films, which are fabricated by improved methods. New insights are provided by high resolution spectroscopy and variable scan rates. Furthermore, we introduce new analytical models in order to understand the spectral changes quantitatively. In contrast to most previous literature, we find that the plasmonic signal is caused almost entirely by the formation of ionic complexes on the metal surface, most likely gold chloride in this study. The refractometric sensing effect from the ions in the electric double layer can be fully neglected, and the charging of the metal gives a surprisingly small effect for these systems. Our conclusions are consistent for both localized nanoparticle plasmons and propagating surface plasmons. We consider the results in this work especially important in the context of combined electrochemical and optical sensors.