Modulation\nof Ion Transport in Nanopores Using Polyethylene\nGlycol

Ion transport in nanopores is crucial for various biological\nand\ntechnological processes, exhibiting unique behaviors compared to bulk\nsolutions. In this study, we systematically explore how polyethylene\nglycol (PEG) modulates ion transport within a conical nanopore. Our\nexperiments reveal that introducing PEG into the ionic solution induces\na reversal in ion current rectification (ICR). We further investigate\nthe impact of PEG concentration, molecular weight, nanopore size,\nand cation type on ion transport. Additionally, we assess three different\nconfigurations of PEG introduction, identifying diffusive flow driven\nby an asymmetric cation distribution within the nanopore as a dominant\ntransport mechanism. Our results confirm that the interactions between\nPEG and cations significantly affect ion transport properties. These\nfindings advance our understanding of macromolecular crowding effects\non ion transport and suggest potential applications in iontronic devices\nand biomolecule sensing.