Journal Article

FZJ-2023-01332

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png On-Chip Electrokinetic Micropumping for Nanoparticle Impact Electrochemistry

Weiß, L. ; Music, E. ; Rinklin, P. ; Banzet, M.FZJ* ; Mayer, D. (Corresponding author)FZJ* ; Wolfrum, B. (Corresponding author)

2022
American Chemical Society Columbus, Ohio

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Please use a persistent id in citations: doi:10.1021/acs.analchem.2c02017  doi:10.34734/FZJ-2023-01332

Abstract: Single-entity electrochemistry is a powerful technique to study the interactions of nanoparticles at the liquid–solid interface. In this work, we exploit Faradaic (background) processes in electrolytes of moderate ionic strength to evoke electrokinetic transport and study its influence on nanoparticle impacts. We implemented an electrode array comprising a macroscopic electrode that surrounds a set of 62 spatially distributed microelectrodes. This configuration allowed us to alter the global electrokinetic transport characteristics by adjusting the potential at the macroscopic electrode, while we concomitantly recorded silver nanoparticle impacts at the microscopic detection electrodes. By focusing on temporal changes of the impact rates, we were able to reveal alterations in the macroscopic particle transport. Our findings indicate a potential-dependent micropumping effect. The highest impact rates were obtained for strongly negative macroelectrode potentials and alkaline solutions, albeit also positive potentials lead to an increase in particle impacts. We explain this finding by reversal of the pumping direction. Variations in the electrolyte composition were shown to play a critical role as the macroelectrode processes can lead to depletion of ions, which influences both the particle oxidation and the reactions that drive the transport. Our study highlights that controlled on-chip micropumping is possible, yet its optimization is not straightforward. Nevertheless, the utilization of electro- and diffusiokinetic transport phenomena might be an appealing strategy to enhance the performance in future impact-based sensing applications

Keyword(s): Chemistry (2nd)

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Contributing Institute(s):

1. Bioelektronik (IBI-3)

Research Program(s):

1. 5241 - Molecular Information Processing in Cellular Systems (POF4-524) (POF4-524)

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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