Artificial Synapse: Spatiotemporal Heterogeneities in Dopamine Electrochemistry at a Carbon Fiber Ultramicroelectrode

Baoping Chen; David Perry; James Teahan; Ian J McPherson; James Edmondson; Minkyung Kang; Dimitrios Valavanis; Bruno G Frenguelli; Patrick R Unwin

doi:10.1021/acsmeasuresciau.1c00006

Artificial Synapse: Spatiotemporal Heterogeneities in Dopamine Electrochemistry at a Carbon Fiber Ultramicroelectrode

ACS Meas Sci Au. 2021 Jul 1;1(1):6-10. doi: 10.1021/acsmeasuresciau.1c00006. eCollection 2021 Aug 18.

Authors

Baoping Chen¹, David Perry¹, James Teahan¹, Ian J McPherson¹, James Edmondson¹, Minkyung Kang¹, Dimitrios Valavanis¹, Bruno G Frenguelli¹, Patrick R Unwin¹

Affiliation

¹ Department of Chemistry, Molecular Analytical Science Centre for Doctoral Training, and School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom.

Abstract

An artificial synapse is developed that mimics ultramicroelectrode (UME) amperometric detection of single cell exocytosis. It comprises the nanopipette of a scanning ion conductance microscope (SICM), which delivers rapid pulses of neurotransmitter (dopamine) locally and on demand at >1000 defined locations of a carbon fiber (CF) UME in each experiment. Analysis of the resulting UME current-space-time data reveals spatiotemporal heterogeneous electrode activity on the nanoscale and submillisecond time scale for dopamine electrooxidation at typical UME detection potentials. Through complementary surface charge mapping and finite element method (FEM) simulations, these previously unseen variations in electrochemical activity are related to heterogeneities in the surface chemistry of the CF UME.