Performing aCGDE while applying a constant potential at an AE placed close to the PWE (step B1: Figs. 2f and j red curves), a large negative current density is recorded at the AE. The current density is several orders of magnitude larger compared to the redox currents obtained without aCGDE in step A. In contrast, much less negative current densities are recorded when the AE is placed far from the PWE (blue curves). We assume that the voltage drop between the PCE and PWE changes the electrolyte potential not only between the plasma electrodes but also further away from these electrodes in the electrochemical cell. Hence, depending on the position of the electrochemical electrodes, the potential at the AE cannot be controlled properly. In addition, the currents recorded between the PWE and PCE are fluctuating strongly, which induces changes in the electric field and in turn induces a strong noise in the current densities recorded at the AE in step B1. Note that the effect of electric fields on auxiliary electrodes is not unknown and is for example explored in ohmic microscopy and bipolar electrochemistry. Overall, to derive a more meaningful conclusion, the effect of voltage drop on auxiliary electrodes will be discussed elsewhere using an electrochemical cell with a more defined geometry, which also allows a more precise positioning of the different electrodes.