Electrophoretic translocation of star-shaped polymers in single solid-state nanopore

The translocation of linear polymers in nanopores has been extensively studied, while the investigation of polymers with diverse architectures, particularly star-shaped polymers, has remained relatively less explored. One of the main challenges lies in the complexity of sample preparation. In this study, we employ multi-armed poly(ethylene glycol) (PEG) to address this challenge in the investigation of electrophoretic translocation behavior of star polymers. The influences of nanopore size (d), applied voltage (V_m), and the number of arms (f) on the dwell time (τ), polymer capture rate, and the conformation of polymer during translocation are examined. The results revealed a linear correlation between capture rate and fV_m, while τ demonstrates a linear relationship with f/V_m. Intriguingly, star-shaped polymers with f_in > f_out exhibit potential for successful translocation, contrary to previous findings where f_in < f_out, where f_in and f_out correspond to the number of arms inside and outside the nanopore when the polymer chain being captured. Notably, the optimal f_in increased from 0.25f to 0.5f as the pore size increased, where the degree of confinement (R_h/d) decreased. These findings offer new insights into the translocation behavior of star-shaped polymers in confined environments and highlight PEG-based polymers as an effective model for studying polyelectrolyte dynamics.