Sensing with ion current rectifying solid-state nanopores

Abstract

This review gives a current opinion on the state of the art of ion rectifying solid-state nanopore sensors, as well as on the recent directions and challenges of the field, focusing in particular on the progress made in the last two to three years. The review explains the phenomenon of ion current rectification in geometrically asymmetric nanopores and the principle of sensing with these systems. Aside from the conventional approach of analyte immobilization onto the pore surface, some intriguing sensing schemes that decouple the pore selectivity from the surface and promise a more flexible sensing approach are also presented. Lastly, an overview of the recent effort towards amplifying the ion currents and the rectification of these sensors is given, followed by a brief discussion of future perspectives for the field. • Decoupling the selectivity of detection from the pore surface can lead to universal sensors. • Maximizing ion current magnitude and rectification ratios is needed to enhance sensitivity. • Various mesopores and micropores have shown enhanced current magnitudes or rectification. • Examples of practical ion current rectifying nanopore sensors highlight real-world potential.