School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 10049, P. R. China.
Anal Chem. 2021 May 25;93(20):7394-7398. doi: 10.1021/acs.analchem.1c01382. Epub 2021 May 12.
Exploring the electrochemical collision features at nanoelectrodes is highly desirable for revealing new physical insights and further expanding its applications at smaller spaces. Herein, we study the collision processes of single silver nanoparticles (AgNPs) inside carbon nanopipettes (CNPs). Results show that AgNPs undergo multiple collision and oxidation processes prior to fully oxidation after entering into the CNPs. Different from the disk electrodes, the produced Ag cannot immediately diffuse away from the cavity and will be reduced once switching to reductive potentials. More intriguingly, we observe discrete cathodic spikes from the Ag reduction, which are presumably due to the negatively charged carbon surface confined in the CNPs. The elucidated collision features in a CNP would enable its better usage for single entity measurements at confined spaces.
探索纳米电极上的电化学碰撞特征对于揭示新的物理见解和在更小的空间进一步扩展其应用具有重要意义。在此，我们研究了单个银纳米颗粒（AgNPs）在碳纳米管（CNPs）内的碰撞过程。结果表明，AgNPs 在进入 CNPs 后完全氧化之前，经历了多次碰撞和氧化过程。与盘电极不同的是，产生的 Ag 不能立即从腔室中扩散出去，一旦切换到还原电位，它将被还原。更有趣的是，我们从 Ag 的还原中观察到离散的阴极尖峰，这可能是由于带负电荷的碳表面被限制在 CNPs 中。在 CNPs 中阐明的碰撞特征将使其能够更好地用于在受限空间中进行单个实体测量。
