Ion‐Current Rectification in Nanopores and Nanotubes with Broken Symmetry

Abstract This article focuses on ion transport through nanoporous systems with special emphasis on rectification phenomena. The effect of ion‐current rectification is observed as asymmetric current–voltage ( I–V ) curves, with the current recorded for one voltage polarity higher than the current recorded for the same absolute value of voltage of opposite polarity. This diode‐like I–V curve indicates that there is a preferential direction for ion flow. Experimental evidence that ion‐current rectification is inherent to asymmetric, e.g., tapered, nanoporous systems with excess surface charge is provided and discussed. The fabrication and operation of asymmetric polymer nanopores, gold nanotubes, glass…