Figure 2

(a) Photograph of the electrolyte container glued to a gold substrate prepared by thermal evaporation on a glass slide, indicating the approximate positions of the leads used to apply the bias voltage (0.3 V) and of the probe lead (working electrode position) (positions 1 or 2); (b) and (c) variation of the EDL potential at positions 2 and 1, respectively, upon application of a bias (red), evidencing both the reverse variation of the EDL potential at the two positions for the same bias and its reversibility; (d) enlarged representation of the EDL potential variation of (b) when the bias changes from + 0.3 V to − 0.3 V, evidencing a delay between 90 and 40 ms in the EDL response, which is likely limited by the setup used.