Transport behaviour of chaotropic and kosmotropic anions within unmodified and polyelectrolyte modified conical nanopore

Abstract

The study examined the transport behaviour of chaotropic and kosmotropic anions within a negatively charged and a positively charged conical nanopore. The chaotropic and kosmotropic anions did not alter the surface charge of the unmodified nanopore. All of the anions exhibited a positive rectified current voltage (I-V) curve when exposed to an unmodified conical nanopore. The surface charge of the unmodified nanopore was switched to positive through functionalisation with a positively charged polyelectrolyte. The chaotropic anion may have adsorbed on the hydrophobic regions of the surface, culminating in surface charge neutralisation. Among the kosmotropic anions, chromate, which is a multivalent anion, altered the surface charges of the modified nanopore. Additionally, ionic transport behaviour of K⁺ ions was examined under a range of different pH conditions.