The Influence of Supporting Ions on the Electrochemical Detection of Individual Silver Nanoparticles: Understanding the Shape and Frequency of Current Transients in Nano-impacts.
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.
Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425, Jülich, Germany.
Kay J
http://orcid.org/0000-0003-4862-7438
KJ
Krause
Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425, Jülich, Germany.
Fabian
F
Brings
Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425, Jülich, Germany.
Jan
J
Schnitker
Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK.
Enno
E
Kätelhön
Neuroelectronics, MSB, Department of Electrical and Computer Engineering, Technical University of Munich (TUM), Boltzmannstr. 11, 85748, Garching, Germany.|Bernstein Center for Computational Neuroscience Munich, Germany.
Philipp
P
Rinklin
Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425, Jülich, Germany.
Dirk
D
Mayer
Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK.
Richard G
RG
Compton
MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE, Enschede, The Netherlands.
Serge G
SG
Lemay
Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425, Jülich, Germany.
Andreas
A
Offenhäusser
Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, 52425, Jülich, Germany.|Neuroelectronics, MSB, Department of Electrical and Computer Engineering, Technical University of Munich (TUM), Boltzmannstr. 11, 85748, Garching, Germany.|Bernstein Center for Computational Neuroscience Munich, Germany.
Bernhard
B
Wolfrum
electrochemistry; nanoparticles; oxidation; silver