Biomimetic Nanocones that Enable High Ion Permselectivity

Artificial counterparts of conical-shaped transmembrane protein channels are of interest in biomedical sciences for biomolecule detection and selective ion permeation based on ionic size and/or charge differences. However, industrial-scale applications such as seawater desalination, separation of mono- from divalent cations, and treatment of highly-saline industrial waste effluents are still big challenges for such biomimetic channels. A simple monomer seeding experimental approach is used to grow ionically conductive biomimetic charged nanocone pores at the surface of an acid-functionalized membrane. These readily scalable nanocone membranes enable ultra-fast cation permeation (Na+=8.4x vs. Mg2+=1.4x) and high ion charge selectivity (Na+/Mg2+=6x) compared to the commercial state-of-the-art permselective membrane (CSO, Selemion, Japan) owing to negligible surface resistance and positively charged conical pore walls.