pH-Regulated nanopore conductance with overlapped electric double layers

• A model for the ionic conductance in a nanopore with overlapped electric double layer is derived.
• Surface chemical reactions, Stern layer, and the presence of H+ and OH− ions are considered.
• Model is verified by experimental data of conductance in silica nanopores.
• Stern layer effects on the zeta potential and conductance are significant at high pH.

There has been a significant growth of interest in single nanopore ionic devices that could control the transport of ions and rectify ionic current. To improve the advance of relevant nanofluidic devices, a model is derived for the first time to investigate the zeta potential and ionic conductance of a cylindrical nanopore with overlapped electric double layer as functions of pH, salt concentration as well as the Stern layer capacitance. The developed model is validated by the experimental data of the nanopore conductance. Results show that in addition to the magnitudes, the relevant behaviors of zeta potential and conductance of the nanopore might be significantly influenced by the Stern layer.

A model for the charge and ionic conductance in a pH-regulated nanopore with overlapped electric double layer is developed and validated.Figure optionsDownload as PowerPoint slide