Mimicking biological ion channels using boron nitride nanotubes

Biological ion channels act to control a wide variety of cell functions by regulating the movement of charged ions across the cell membrane. The ability to mimic these ion channels would facilitate the development of unique biosensors, filtration devices and antibiotics. We demonstrate, using molecular and stochastic dynamics, that boron nitride nanotubes with various radii embedded in a silicon nitride membrane have the ability to mimic some of the important functions of various biological ion channels. In particular, we examine the free energy profile, and the current-voltage-concentration profiles for various ions. We find that nanotubes with a radius of 3.45, 4.83 and 5.52 Å are selectively permeable to water molecules, positive ions (cations) and negative ions (anions), respectively.