(232d) Current Rectification in a Nanopore with Biomimetic Functional Groups

Biological Ion channels, which generally have asymmetric, non-cylindrical structure, in cell membranes play an essential role, such as gate to regulate water, ionic species, and small molecules through the membrane. Inspired by actual physiologic environments, the nanoscale channels can be stimulated by pH and salt concentration differences through two sides of channels, and hence might have interesting and unique ion transport phenomena. Herein, we fabricate a conical nanopore with biomimetic lysine groups by two step functionalization processes. The polyacrylic acid polymer chains were first coated on the inner surface of conical nanopore using the surface plasma polymerization technique, followed by the grafted modification of lysine groups by wet solution chemical reaction. Results show that the ion current rectification in the prepared biomimetic nanopore is dependent on the solution pH and salt concentration. Moreover, the behaviors of current rectification is different for two reservoirs connected to the nanopore with different solution pHs.