Characterization of ultrananocrystalline diamond microsensors for in vivo dopamine detection

We show the technical feasibility of coating and micro patterning boron-doped ultrananocrystalline diamond (UNCD^®) on metal microwires and of applying them as microsensors for the detection of dopamine in vivo using fast-scan cyclic voltammetry. UNCD electrode surface consistently generated electrochemical signals with high signal-to-noise ratio of >800 using potassium ferrocyanide-ferricyanide redox couple. Parylene patterned UNCD microelectrodes were effectively applied to detect dopamine reliably in vitro using flow injection analysis with a detection limit of 27 nM and in the striatum of the anesthetized rat during electrical stimulation of dopamine neurons.