The Influence of Supporting Ions on the Electrochemical Detection of Individual Silver Nanoparticles: Understanding the Shape and Frequency of Current Transients in Nano-impacts

Kay J. Krause, Fabian Brings, Jan Schnitker, Enno Kätelhön, Philipp Rinklin, Dirk Mayer, Richard G. Compton, Serge G. Lemay, Andreas Offenhäusser, Bernhard Wolfrum*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

17 Citations (Scopus)

Abstract

We report the influence of electrolyte composition and concentration on the stochastic amperometric detection of individual silver nanoparticles at microelectrode arrays and show that the sensor response at certain electrode potentials is dependent on both the conductivity of the electrolyte and the concentration of chloride ions. We further demonstrate that the chloride concentration in solution heavily influences the characteristic current spike shape of recorded nanoparticle impacts: While typically too short to be resolved in the measured current, the spike widths are significantly broadened at low chloride concentrations below 10 mm and range into the millisecond regime. The analysis of more than 25 000 spikes reveals that this effect can be explained by the diffusive mass transport of chloride ions to the nanoparticle, which limits the oxidation rate of individual silver nanoparticles to silver chloride at the chosen electrode potential.

Original languageEnglish
Pages (from-to)4638-4643
Number of pages6
JournalChemistry: a European journal
Volume23
Issue number19
DOIs
Publication statusPublished - 3 Apr 2017

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Keywords

  • electrochemistry
  • nanoparticles
  • oxidation
  • silver

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