There is also both a strong temperature dependence and scanning periodicity dependence on both fouling-induced loss in sensor response and shifts in frequency response. Over 7 days of testing, MCH sensors repeatedly scanned at 4 ˚C only showed a loss of ¼ th of maximum response, whereas MCO based sensors showed virtually no loss in sensor response (Figure ). These results further support our previous conclusion that fouling is largely temperature dependent, which includes the subsequent rearrangement that can hinder aptamer mobility and sensor response to analyte. Regarding a dependence on the frequency of scanning, sensors scanned once-a-day in serum at 4 ˚C suffered greater reductions in their maximum sensor response compared to those repeatedly scanned at 4 ˚C (see Supplemental Figure ). These results further suggest a dependance for biofouling on how often scanning is performed, likely due to electric field perturbation and reorganization of the biofouled layer, consistent with our previous data (Figure ) and discussion in this paper.