Nanopore-based biosensors: The interface between ionics and electronics

Techniques for translating the binding or the activity of single molecules directly into electrical signals are of interest for both fundamental and applied science. A paper in this issue describes experiments in which the ionic current through a biological nanopore is employed both to control and to monitor the attachment of individual DNA polymerase enzymes to their binding site on a single DNA molecule. This Perspective briefly sketches some of the factors that ultimately limit the performance of such nanoscale sensors, emphasizing in particular the interface between nanofluidic systems and external control electronics.