The Influence of Supporting Ions on the Electrochemical Detection of Individual Silver Nanoparticles: Understanding the Shape and Frequency of Current Transients in Nano‐impacts. Issue 19 (20th March 2017)

• Record Type: Journal Article
• Authors: Krause, Kay J.; Brings, Fabian; Schnitker, Jan; Kätelhön, Enno; Rinklin, Philipp; Mayer, Dirk; Compton, Richard G.; Lemay, Serge G.; Offenhäusser, Andreas; Wolfrum, Bernhard
• Is Part Of: Chemistry. Volume 23:Issue 19(2017)
• Page Start: 4638
• Page End: 4643
• Publication Date: 2017-03-20
• Subjects: electrochemistry -- nanoparticles -- oxidation -- silver; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201605924
• Languages: English
• ISSNs: 0947-6539

Abstract

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. Abstract : Spiking silver : The influence of electrolyte composition and concentration on the stochastic amperometric detection of individual silver nanoparticles is reported. While typically too short to be resolve in the measured current, the spike widths are significantly broadened at small chloride concentrations below 10 mm . 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 (see figure).