Towards electrochemical control of pH for regeneration of biosensors

Most affinity-based biosensors are designed to be single-use devices, based on the measurement of irreversible binding events, which makes longitudinal monitoring resource-intensive, and typically prohibits the measurement of analyte fluctuations over time using the same device. Selective reversal of biorecognition events, i.e., regeneration, may enable repeated and longitudinal use of affinity-based biosensors; however, typical regeneration methods utilize additional chemical reagents, requiring longer processing times and increasing the likelihood of operator error. The development of a “solid-state” regeneration method provides significant value for extending the utility of affinity-based biosensors, such as electrochemical immunosensors and aptasensors. Herein, we report the characterization of a method for electronically controlling pH without additional reagents. Palladium was used to induce pH swings in aqueous electrolytes and buffers by application of an electric potential. The developed system was able to affect acidic and basic pH changes of ± 4. The efficacy of this method was further demonstrated by reversing common affinity-binding complexes and compared to conventional glycine-based regeneration.