Engineering Electrostatic Repulsion of Metal Nanoparticles for Reduced Adsorption in Single-Impact Electrochemical Recordings
Engineering Electrostatic Repulsion of Metal Nanoparticles for Reduced Adsorption in Single-Impact Electrochemical Recordings
复制标题
DOI：
10.1021/acsanm.1c01507
复制
发表时间：
2021-07
影响因子：
5.9
通讯作者：
L. Weiß;Emir Music;P. Rinklin;Lea Straumann;Leroy Grob;D. Mayer;B. Wolfrum
中科院分区：
文献类型：
--
作者：
L. Weiß;Emir Music;P. Rinklin;Lea Straumann;Leroy Grob;D. Mayer;B. Wolfrum
随机冲击电化学是一种很有前途的概念，以检测溶液中的超低浓度的纳米粒子。然而，统计上可靠的传感器输出需要适当数量的观察到的纳米粒子碰撞事件。这里，可单独寻址的电极的阵列允许增加有效检测面积，从而增加碰撞事件的数量，而不牺牲信噪比。然而，与此同时，这些测量通常会增加系统的表面积与体积比，导致吸附对可用颗粒数量的影响更大。我们通过控制靠近检测电极的电极-电解质界面来解决纳米颗粒吸附的这个问题。我们使用一个直接的纳米碰撞实验来证明，带负电荷的表面导致静电排斥，这导致检测到的碰撞事件的数量增加了2.5倍。除了这种改进的传感器性能，可调屏蔽电极提供了一个多功能的工具来研究纳米颗粒在固液界面的吸附。
Stochastic impact electrochemistry is a promising concept to detect ultralow concentrations of nanoparticles in solution. However, statistically reliable sensor outputs require an appropriate number of observed nanoparticle collision events. Here, arrays of individually addressable electrodes allow increasing the effective detection area, and thereby the number of collision events, without sacrificing the signal-to-noise ratio. At the same time, however, these measurements typically increase the surface-to-volume ratio of the system, leading to a stronger influence of adsorption on the number of available particles. We address this issue of nanoparticle adsorption by controlling the electrode–electrolyte interface close to the detection electrodes. We use a direct nanoimpact experiment to demonstrate that a negatively charged surface leads to electrostatic repulsion, which results in a 2.5-fold increase in the number of detected collision events. Adding to this improved sensor performance, a tunable shield electrode offers a versatile tool to study nanoparticle adsorption at the solid–liquid interface.