Fig. 3 illustrates the cyclic voltammograms for [Ru(NH3)6]2+/3+ and [Fe(CN6)]3−/4− redox couples recorded using the polished electrode (dashed curves) and the activated electrode (solid curves). Comparison of these voltammograms indicated several noticeable effects of the activation procedure on the CSE response characteristics. Firstly, the activation of the electrode surface resulted in a significant decreasing peak separation (ΔEp = Epa − Epc) for each of the redox couples examined. At the same time, the corresponding peak currents became higher, especially in case of positively charged complex ions Ru(NH3)6]2+/[Ru(NH3)6]3+. In addition, higher background currents were observed upon activation. The above results can be attributed to large surface area, surface functional groups and high heterogeneous electron-transfer reactivity of the activated CSE. According to the Randles–Sevcik equation [32], the active area of the polished CSE and the ACSE were calculated to be 7.67 mm2 and 12.78 mm2, correspondingly.