title: Patternable nanowire sensors for electrochemical recording of dopamine.
abstract: Spatially resolved electrochemical recording of neurochemicals is difficult due to the challenges associated with producing nanometer-scale patternable and integrated sensors. We describe the lithographic fabrication and characterization of patternable gold (Au) nanowire (NW) based sensors for the electrochemical recording of dopamine (DA). We demonstrate a straightforward NW-size-independent approach to align contact pads to NWs. Sensors, with NW widths as small as 30 nm, exhibited considerable insensitivity to scan rates during cyclic voltammetry, a nonlinear increase in oxidation current with increasing NW width, and the selectivity to measure submaximal synaptic concentrations of DA in the presence of interfering ascorbic acid. The electrochemical sensitivity of Au NW electrode sensors was much larger than that of Au thin-film electrodes. In chronoamperometric measurements, the NW sensors were found to be sensitive for submicromolar concentration of DA. Hence, the patternable NW sensors represent an attractive platform for electrochemical sensing and recording.
authors.affiliation: Department of Chemical and Biomolecular Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.
authors.forename: P
authors.initials: P
authors.lastname: Tyagi
authors.forename: D
authors.initials: D
authors.lastname: Postetter
authors.forename: D L
authors.initials: DL
authors.lastname: Saragnese
authors.forename: C L
authors.initials: CL
authors.lastname: Randall
authors.forename: M A
authors.initials: MA
authors.lastname: Mirski
authors.forename: D H
authors.initials: DH
authors.lastname: Gracias
mesh_terms: D004298:Dopamine / Q000032:analysis*; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D006046:Gold; D004298:Dopamine