Steric effects and ionic size in deoxyribonucleic acid electrophoretic translocation through nanopores

This study examines, for the first time, the steric interactions of ionic species and their impact on the electrophoretic translocation of deoxyribonucleic acid (DNA) through solid-state nanopores filled with potassium chloride (KCl) electrolyte, using numerical methods. The Carnahan–Starling model is employed to incorporate these interactions into the framework. The findings reveal significant alterations in translocation velocity and electroosmotic flow due to reduced counterion concentration and surface charge screening in the presence of steric effects. These changes notably influence the electrokinetic behavior of DNA, particularly at higher surface charge densities. Additionally, the analysis was extended to include a more realistic consideration of DNA hydrodynamic slippage. By exploring various scenarios during the translocation process under steric influences, it was concluded that incorporating these effects is crucial for accurate modeling and design in nanopore-based applications, ultimately enhancing our understanding of DNA dynamics at the nanoscale.