Fig. 8.

Monolayer stability under continuous interrogation. We first interrogated the electrodes negatively using a voltage window similar to the one used with benchmark E-AB sensors. A Gold electrodes modified with hexanethiol (HxSH) show almost no change in charging current after 48 h of continuous interrogation. B In contrast, GC electrodes modified with aminohexane (Hx) show a clear increase in charging current due to the reduction and removal of the grafted amine groups. C Side-by-side comparison of changes in charging currents measured at − 0.2 V for both sets of electrodes. D Interrogating positively, alkanethiol-coated gold electrodes presented a significant increase in charging currents. E In contrast, the charging currents of aminohexane-grafted GC electrodes were stable for 48 h. F Side-by-side comparison of charging currents vs time showing that, in this voltage window, aminohexane-grafted GC electrodes display a far superior stability. Solid, dotted traces, and shades correspond to the average and standard deviation of 4 electrodes, respectively