Figure 1.

Proposed mechanisms of monolayer degradation and solutions for reaching multi-day stability for electrochemical aptamer sensors. (A) Thermal desorption and/or desorption mediated by serum solutes can be partially mitigated by increasing alkylthiol chain length while (B) Electrochemical scanning can be optimized to reduce both electric field induced desorption and spontaneous monolayer oxidation. (C) Enzymatic attack of aptamer probes is a concern that can largely be circumvented by utilizing non-native DNA chemistry. (D) While biofouling alters sensor signaling properties, membrane protection and surface chemistry modifications can mitigate these detrimental changes and retain sensor performance in multiday operation.