Novel conduction behavior in nanopores coated with hydrophobic molecules

Nanopores that are hydrophilic either by the nature of their pore surface or after suitable treatment are well studied in the context of solid-state nanopores. The ionic conduction in these nanopores typically exhibit a near no-concentration-dependence region low concentrations of salt (\textless 1 mM salt concentrations), followed by the high concentration region where it is proportional to the concentration. A simple cylindrical model for pore conduction can explain these behaviors based on surface and bulk conduction of the ions in the buffer solution [Smeets et al 2006 Nano Letters \textbf{6}, 89]. However, in nanopores coated with hydrophobic pores we find that the pore conductance is $\sim$ c$^{0.5}$ (c: concentration). This behavior is in shark contrast with the behavior of hydrophilic pores. We will present these results for different hydrophobic molecular coatings that exhibit this behavior.