NanoPhotonics Centre, Cavendish Laboratory, University of Cambridge , Cambridge CB3 0HE, U.K.
Department of Chemistry, King's College London , London SE1 1DB, U.K.
Nano Lett. 2017 Aug 9;17(8):4840-4845. doi: 10.1021/acs.nanolett.7b01676. Epub 2017 Jul 17.
We study in real time the optical response of individual plasmonic nanoparticles on a mirror, utilized as electrodes in an electrochemical cell when a voltage is applied. In this geometry, Au nanoparticles are separated from a bulk Au film by an ultrathin molecular spacer. The nanoscale plasmonic hotspot underneath the nanoparticles locally reveals the modified charge on the Au surface and changes in the polarizability of the molecular spacer. Dark-field and Raman spectroscopy performed on the same nanoparticle show our ability to exploit isolated plasmonic junctions to track the dynamics of nanoelectrochemistry. Enhancements in Raman emission and blue-shifts at a negative potential show the ability to shift electrons within the gap molecules.
我们实时研究了施加电压时作为电化学池电极的镜面上单个等离子体纳米粒子的光学响应。在这种几何形状中，通过超薄膜状分子间隔物将 Au 纳米粒子与大块 Au 薄膜隔开。纳米粒子下方的纳米级等离子体热点局部揭示了 Au 表面上的修饰电荷以及分子间隔物的极化率的变化。在同一纳米粒子上进行的暗场和拉曼光谱分析表明，我们有能力利用孤立的等离子体结来跟踪纳米电化学的动力学。在负电势下，拉曼发射的增强和蓝移表明能够在间隙分子内移动电子。
