Modulating nanopore size and ion transport using (Anti)-Polyelectrolyte effects inspired by the nuclear pore complex

This study explores the modulation of nanopore size and ion transport through (anti)-polyelectrolyte effects, which is inspired by the nuclear pore complex. We aimed to control ionic selectivity and rectification by applying these effects to synthetic nanopores. Single bicylindrical nanopores were fabricated on the PET membranes and functionalized with PEI/HA or PLL/PAA polyelectrolyte layers. Varying the structural and charge characteristics under different pH levels and ionic strengths revealed that at low salt concentrations, charge density and surface charge polarity significantly impacted ion selectivity and transport. At higher concentrations, conformational changes in the polyelectrolytes influenced the conductance via volume expansion or compaction. Our findings highlight the distinct roles of charge inversion and molecular expansion in nanopore transport, which can be modulated by pH and ionic environment. This work provides insights for developing highly selective ion channels with potential applications in filtration, biosensing, and nanofluidics, where precise ion transport and selective rectification are essential.