Interference or crosstalk of coexisting redox species results in overlapping of electrochemical signals, and it is a major hurdle in sensor development. In nanogap sensors, redox cycling between two independently biased working electrodes results in an amplified electrochemical signal and an enhanced sensitivity. Here, we report new strategies for selective sensing of three different redox species in a nanogap sensor of a 2 fL volume. Our approach relies on modulating the electrode potentials to define specific potential windows between the two working electrodes; consequently, specific detection of each redox species is achieved. Finite element modeling is employed to simulate the electrochemical processes in the nanogap sensor, and the results are in good agreement with those of experiments.@en

We propose a new geometry for nanogap electrochemical sensing devices. These devices consist of two closelyspaced side-by-side electrodes which work under redox cycling conditions. Usingfinite element simulations,we investigate the effects of different geometric parameters on the redox cycling signal amplification to gaininsight into the electrochemical sensing performance of the device design. This will allow optimizing the sensorperformance of devices to be fabricated in the future@en