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Carbon Nanotube Fiber Microelectrodes Show a Higher Resistance to Dopamine Fouling
journal contribution
posted on 2016-02-19, 01:56 authored by Wolfgang Harreither, Raphaël Trouillon, Philippe Poulin, Wilfrid Neri, Andrew G. Ewing, Gulnara SafinaWe have compared the properties and
resistance to DA fouling of
a carbon nanotube fiber (CNTF) microelectrode to a traditional carbon
fiber (CF) microelectrode. These two materials show comparable electrochemical
activities for outer-sphere and inner-sphere redox reactions. Although
the CNTF might have a higher intrinsic RC constant, thus limiting
its high-frequency behavior, the CNTF shows a significantly higher
durability than the CF in terms of electrode stability. During constant
oxidation of 100 μM DA, the signal measured by the CNTF microelectrode
shows a 2-h window over which no decrease in current is observed.
Under the same conditions, the current obtained at the CF microelectrode
decreases by almost 50%. A model of the fouling process, assuming
the formation of growing patches of insulator on the surface, has
been compared to the data. This model is found to be in good agreement
with our results and indicates a growth rate of the patches in the
0.1–2 nm s–1 range.