Response time of nanofluidic electrochemical sensors.

Nanofluidic thin-layer cells count among the most sensitive electrochemical sensors built to date. Here we study both experimentally and theoretically the factors that limit the response time of these sensors. We find that the key limiting factor is reversible adsorption of the analyte molecules to the surfaces of the nanofluidic system, a direct consequence of its high surface-to-volume ratio. Our results suggest several means of improving the response time of the sensor, including optimizing the device geometry and tuning the electrode biasing scheme so as to minimize adsorption.