Biomimetic ionic rectifier systems: Asymmetric modification of single nanochannels by ion sputtering technology

摘要

Single nanochannels as promising candidates for mimicking the ionic rectification of biological ion channels have attracted intense interest in recent years. Most rectifying properties of the biomimetic single nanochannels were studied with asymmetric conical structures. In this article, we develop biomimetic ionic rectifier systems from single hour glass-shaped polymeric nanochannels using asymmetric ion sputtering of Au and Pt. X-ray photoelectron spectra and contact angle measurements were used to determine Au and Pt depositions on the polymeric membranes. Four different composed nanochannels were fabricated with either symmetric or asymmetric sputtering method. The ionic transport properties of these nanochannels were characterized by transmembrane current measurements. The results reveal that the nanochannels with asymmetric compositions can rectify ionic current effectively. This work provides a basic platform to obtain rectifications in symmetric nanochannels, moreover, the channels would also have promising applications in intelligent systems because of their biomimetic ionic transport properties and convenience to be modified further.