Electrochemical Properties of Different Carbon-Fiber Microelectrodes Using Fast-Scan Cyclic Voltammetry

In this study, fast-scan cyclic voltammetry (FSCV) was used to compare responses to neurochemicals of various carbon fibers, with different conductivities and carbon precursors. Pitch-based P-25 and P-55 fibers were compared to polyacrylonitrile-based T-650 and HM fibers. Highly conductive fibers such as P-55s or HMs have larger background charging currents than lower conductivity fibers. Using a standard waveform, PAN-based fibers and less conductive fibers experience faster kinetics. With a more positive switching potential, higher conductivity fibers show faster kinetics for catecholamines and larger oxidation peak currents for anions such as ascorbic acid and 3,4-dihydroxyphenylacetic acid (DOPAC). Conductivity was found to have the greatest impact on fiber performance, but the nature of its effect depends on the waveform used and the analyte detected.