Voltammetric experiments were carried out in a 10 mL glass electrochemical cell using a portable PalmSens4 potentiostat/galvanostat (PalmSens BV, Houten, The Netherlands) in combination with a cable connector for SPEs (DRP-CAC 71606, Metrohm DropSens, Asturias, Spain). The instrument was controlled with the PSTrace 5.8 software (PalmSens BV). All measurements were performed at laboratory temperature (22–23 °C).
Electrochemical impedance spectroscopy (EIS) measurements have been performed using Autolab PGSTAT204 potentiostat/galvanostat (Metrohm Autolab, Utrecht, The Netherlands). Measurements were performed in a frequency range from 100 kHz to 20 mHz with 8 points per decade and a 10 mV (peak-to-peak) amplitude of the excitation signal. EIS measurements were performed in a solution containing 10 mM K3[Fe(CN)6] (99.9%, Sigma Aldrich, St. Louis, MO, USA) and 0.1 M KCl (p.a., Carlo Erba Reagents, Milan, Italy).
Commercial SPEs type DRP-C110 were purchased from Metrohm DropSens. These electrodes have a single circular carbon working electrode (4 mm in diameter), a carbon counter electrode, and a silver quasi-reference electrode and are suitable for use in a solution.
Electrochemical impedance spectroscopy (EIS) measurements have been performed using Autolab PGSTAT204 potentiostat/galvanostat (Metrohm Autolab, Utrecht, The Netherlands). Measurements were performed in a frequency range from 100 kHz to 20 mHz with 8 points per decade and a 10 mV (peak-to-peak) amplitude of the excitation signal. EIS measurements were performed in a solution containing 10 mM K3[Fe(CN)6] (99.9%, Sigma Aldrich, St. Louis, MO, USA) and 0.1 M KCl (p.a., Carlo Erba Reagents, Milan, Italy).
Commercial SPEs type DRP-C110 were purchased from Metrohm DropSens. These electrodes have a single circular carbon working electrode (4 mm in diameter), a carbon counter electrode, and a silver quasi-reference electrode and are suitable for use in a solution.