Carbon Nanotube-based microelectrodes for enhanced detection of neurotransmitters

Jacobs, Christopher B., Department of Chemistry, University of Virginia
Venton, Jill, Department of Chemistry, University of Virginia
Landers, James, Department of Chemistry, University of Virginia
Harrison, Ian, Department of Chemistry, University of Virginia

Fast-scan cyclic voltammetry FSCV is one of the common techniques used for rapid measurement of neurotransmitters in vivo Carbon-fiber microelectrodes CFMEs are typically used for neurotransmitter detection because of sub-second measurement capabilities ability to measure changes in neurotransmitter concentration during neurotransmission and the small size electrode diameter which limits the amount of damage caused to tissue Cylinder CFMEs typically    m long are commonly used for in vivo experiments because the electrode sensitivity is directly related to the electrode surface area (owever the length of the electrode can limit the spatial resolution of neurotransmitter detection which can restrict experiments in Drosophila and other small model systems )n addition the electrode sensitivity toward dopamine and serotonin detection drops significantly for measurements at rates faster than  (z limiting the temporal resolution of CFMEs While the use of FSCV at carbon-fiber microelectrodes has led to substantial strides in our understanding of neurotransmission techniques that expand the capabilities of CFMEs are crucial to fully maximize the potential uses of FSCV This dissertation introduces new methods to integrate carbon nanotubes CNT into microelectrodes and discusses the electrochemical enhancements of these CNTmicroelectrodes The electrodes are specifically designed with simple fabrication procedures so that highly specialized equipment is not necessary and they utilize Jacobs ii commercially available materials so that the electrodes could be easily integrated into existing systems The electrochemical properties of CNT modified CFMEs are characterized using FSCV and the effect of CNT functionalization on these properties is explored in Chapter  For example CFME modification using carboxylic acid functionalized CNTs yield about a -fold increase in dopamine oxidation current but modification with octadecylamine CNTs results in a negligible change to the signal Chapter  is devoted to the development and characterization of new CNT-Yarn Microelectrodes CNTYME which display a beneficial enhancement in sensitivity and reduction in both electron transfer kinetics and overpotential Chapter  introduces the highspeed dopamine detection capabilities of CNTYMEs almost two orders of magnitude faster than at CFMEs without any compromise in electrochemical sensitivity and discusses how adsorption and desorption relate to this phenomenon

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PHD (Doctor of Philosophy)
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