Though redox tag currents for MCH sensors were shown to sharply increase as the monolayer desorbed (Figure ), this largely suggests a rapid loss in functionality as the increased redox tag current is due to greater ease of electron transfer through a highly defective biofouled layer with numerous pinholes and large unoccupied gold domains compared to a tightly packed MCH layer. MCO sensors on the other hand provided much more stable redox tag currents and voltammograms over 7 days with only minimal increase in oxygen reduction current (Figure ). Similar to how adding two methylene groups to passivation layer molecules (i.e., MCO vs. MCH) creates a larger energy barrier for thermal desorption in PBS (Table , Figure ), increased intermolecular forces between neighboring MCO molecules also makes it more difficult for foulants to act as an energetic bridge for MCO desorption in serum (Figure ). However, once MCO sensor background currents began to increase around day 7, sensor degradation rapidly accelerated and soon resulted in voltammograms with indistinguishable redox tag currents.