Jan 8, 2013
External charges tune ion-selective nanopore
In a recent study, researchers from the Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, have teamed up with scientists from the University of Manchester and Xi'an Jiaotong University to present a design for an ion-selective nanopore (molecular switch) controlled by external charges.
Molecular dynamics simulations performed by the group show that the remarkable selectivity of the system can be switched from predominantly negative to predominantly positive ions and that the magnitude of the ionic flux can be varied by changing the distance of the external charges. The results also suggest that the hydration structures around ions play a prominent role in the selectivity process, which is tuned by the external charge.
The system could act as a voltage sensor by detecting the type of ions across the channel and offers ways to control the behaviour, properties and chemical composition of liquids, as well as a route to developing impurity detectors. Other possible technical applications include nanofluidic PN junctions, field effect transistors and logic devices.
Full details can be found in the journal Nanotechnology.
About the author
Dr Xiaojing Gong is an associate professor at the Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, China. She is using simulation methods to explore ionic-selectivity and water transportation properties across organic or inorganic nanotubes and investigate the growth dynamics of III-nitride semiconductors.