Nanocavity Redox Cycling Sensors for the Detection of Dopamine Fluctuations in Microfluidic Gradients

摘要

Electrochemical mapping of neurotransmitter concentrationsnon a chip promises to be an interesting techniquenfor investigating synaptic release in cellular networks. Innhere, we present a novel chip-based device for the detectionnof neurotransmitter fluctuations in real-time. The chipnfeatures an array of plane-parallel nanocavity sensors,nwhich strongly amplify the electrochemical signal. Thisnamplification is based on efficient redox cycling vianconfined diffusion between two electrodes inside thennanocavity sensors. We demonstrate the capability ofnresolving concentration fluctuations of redox-active speciesnin a microfluidic mixing gradient on the chip. Thenresults are explained by a simulated concentration profilenthatwascalculatedonthebasisofthecoupledNavier-Stokesnand convection-diffusion equations using a finite elementnapproach.