Fig. 3. Characterization of electrode CNT modifications by CV detection of 2 mM ferrocene dimethanol (FDM).

a Representative cyclic voltammograms of bare Au and CNT-coated microdisk and membrane electrodes. b, c Membrane electrodes were tested for scan-rate dependence at the following levels of CNT modification: bare, 2 µL of CNT coating, and 12.5 µL of CNT coating, which exhibited linear behavior of Ipa vs. $\sqrt{\mathrm{\nu }}$ (b). The Au-CNT (12.5 µL) membrane electrode showed a time-dependent reaction to 2 mM FDM, so a 1-min accumulation time was allowed between CV cycles. The obtained Ipa data are plotted against $\sqrt{\mathrm{\nu }}$ in (b) to compare with other coatings and plotted against $\mathrm{\nu }$ in (c) to obtain a better linear fit. The scan rates were 10, 20, 50, 100, and 150 mV/s (n = 3 cycles per electrode). b, c share the same legend