Tuning ion transport and selectivity by a salt gradient in a charged nanopore.
Inspired by ion channels in biological cells where the intracellular and extracellular ionic concentrations are typically different, a salt concentration gradient through a charged nanopore is proposed to actively regulate its ion transport and selectivity. Results obtained show that, in addition to the ion current rectification phenomenon, a reversed ion selectivity of the nanopore occurs when the concentration gradient is sufficiently large. In addition, if the directions of the applied concentration gradient and electric field are identical, a reversed magnified electric field occurs near the cathode side of the nanopore. This induced field can be used to enhance the capture rate of biomolecules and is therefore capable of improving the performance of single biomolecule sensing using nanopores.
Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology , Yunlin 64002, Taiwan.
Li-Hsien
LH
Yeh
Christopher
C
Hughes
Zhenping
Z
Zeng
Shizhi
S
Qian
D017136:Ion Transport; D008962:Models, Theoretical; D058608:Nanopores; D012492:Salts / Q000737:chemistry*
D012492:Salts