TY  - JOUR
AU  - Weiß, Lennart J. K.
AU  - Music, Emir
AU  - Rinklin, Philipp
AU  - Straumann, Lea
AU  - Grob, Leroy
AU  - Mayer, Dirk
AU  - Wolfrum, Bernhard
TI  - Engineering Electrostatic Repulsion of Metal Nanoparticles for Reduced Adsorption in Single-Impact Electrochemical Recordings
JO  - ACS applied nano materials
VL  - 4
IS  - 8
SN  - 2574-0970
CY  - Washington, DC
PB  - ACS Publications
M1  - FZJ-2021-05913
SP  - 8314 - 8320
PY  - 2021
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000692034900073
DO  - DOI:10.1021/acsanm.1c01507
UR  - https://juser.fz-juelich.de/record/904343
ER  -