Figure 11: Typical Nyquist plots obtained for the electrodes in 1 × 10-4 M DA solution (PBS pH 7.0) at a fixed potential of 0.2 V (vs. Ag|AgCl, saturated KCl). The data points are experimental while the solid lines in the spectra represent non-linear squares fits. (d) Represent the circuit used in the fitting of the EIS data in (a-c).