However, a balance in scanning periodicity is needed, because as previously discussed and shown in Figures and, the electric field generated during scanning can also drive desorption of aptamer molecules due to straining of the negatively charged DNA backbone away from the electrode surface. When the same once-a-day scanning tests were performed at 4 ˚C in PBS, redox tag currents for both MCH and MCO sensors were fairly constant and only decreased by ~10% over 7 days, indicating that less frequent scanning resulted in less aptamer desorption. Additionally, the excessive increase in background current observed at 37 ˚C in PBS was not observed for either MCH or MCO sensors scanned once-a-day at 4 ˚C (Figure ), further supporting the conclusion that thermallyinduced alkylthiolate oxidation is largely driving monolayer desorption at elevated temperatures.