With repeated scanning in reduction mode from -0.1 V to -0.5 V (vs. Ag/AgCl), excess electrons are made available to the monolayer during each scan, which could potentially suppress oxidation of neighboring alkylthiolates to disulfides and thus reduce the rate of monolayer desorption. Given that reductive desorption of alkylthiolates has been shown to begin beyond -0.7 V (vs. Ag/AgCl), it is unlikely that repeated scanning within this potential window can induce excessive desorption of passivating molecules. We conclude that under the test conditions presented here, and potentially in most other aptamer sensor experiments, thermal desorption of passivating moieties via oxidation to disulfides is a major driving factor of monolayer degradation and can be partially mitigated via repetitive operation in reduction mode and/or by increasing alkylthiolate length. Longer alkylthiolates (e.g., MCO vs. MCH) are less susceptible to oxidation to disulfides since the oxidation process first requires overcoming van der Waals interactions with neighboring molecules such that the disulfide can form and then diffuse from the electrode surface.