Ag agcl double junction reference electrode

8 × 12 mm² pieces of the nanofiber electrode samples were electrically contacted and placed in a vessel with PBS^-. Impedance spectroscopy was performed by a three-electrode setup containing a glassy-carbon counter electrode and an Ag/AgCl double junction reference electrode (both Metrohm Autolab, Utrecht, The Netherlands). Spectra were recorded in a frequency range from 0.1 to 10 kHz at an alternating sinusoidal voltage of 10 mV with a Potentiostat PGSTAT204 (Metrohm Autolab, Utrecht, The Netherlands). Data was recorded, calculated and fitted with the software Nova 2.1 (Version 2.1, 2016, Metrohm Autolab, Utrecht, The Netherlands).

Electrochemical experiments were performed in a three-electrode cell controlled by an Autolab PGSTAT (Metrohm Autolab B.V., Utrecht, The Netherlands) and Nova software (Version 2.1, Metrohm Autolab B.V., Utrecht, The Netherlands). An Ag/AgCl double-junction reference electrode (Metrohm, Herisau, Switzerland) was used. A coiled platinum wire served as an auxiliary electrode. The supporting electrolytes were 0.05 M pH 3 and pH 7.4 phosphate buffer solutions with the addition of KCl to a concentration of 0.1 M.