Plasmonic nanoparticles offer promise in photoelectrochemistry by enhancing the rate and selectivity of reactions and in sensing by responding optically to local reactions. Optical electrochemical measurements at the single-particle level are necessary for understanding and eventually controlling the role of plasmons in such complex environments. Recently, researchers have developed techniques to optically measure electrochemical reactions at the surface of single nanoparticles and individual aggregates, allowing for the high-throughput screening necessary to resolve subpopulations of active nanoparticle catalysts and identify active sites on aggregate structures. This review highlights single-nanoparticle and nanoparticle aggregate electrochemical techniques and how they can be used to isolate and elucidate the role of surface plasmons in enhancing catalyst activity and sensing electrochemical processes at the nanoscale.

等离子体纳米颗粒通过提高反应的速率和选择性为光电化学提供了希望，并通过光学响应局部反应在传感中提供了希望。为了理解并最终控制等离激元在这种复杂环境中的作用，单粒子水平的光学电化学测量是必不可少的。最近，研究人员开发了用于光学测量单个纳米颗粒和单个聚集体表面的电化学反应的技术，从而可以进行高通量筛选，以解决活性纳米颗粒催化剂的亚群并识别聚集体结构上的活性位点。