Fabrication of Stable Single Nanochannels with Controllable Ionic Rectification

摘要

The fabrication of artificial nanochannels is becoming a focus of attention because, compared with their biological counterparts, they offer flexibility in terms of shape, size, and surface properties for real-world applications.[1,2] At present, there are several approaches to building single nanochannels (nanopores), such as ion-beam sculpting of Si3N4 membranes,[3] Si/ SiO2 membrane shrinking in transmission electron microscopy,[ 4,5] electrochemical etching of glass membranes,[6] and chemical etching of single-track polymer membranes.[7] Because the nanochannel is small enough for interactions between the channel surface and chemical species in the solution, the chemical modification of the nanochannel surface confers great flexibility in developing functional nanochannel materials.[8] Even though several solution methods[9–13] of coating nanochannels with functional molecules, which enable the size and ion-transport properties of the nanochannels to be easily tuned, have been developed during the past few years, how to endow nanochannels with asymmetric chemical properties is still a challenging task.