Kinetic control and entropic barrier modulation of protein unfolding during translocation through stepped graphene nanopores

Abstract

, a critical rate mismatch occurs: the excessive drift velocity outpaces the unfolding rate, triggering lateral buckling and irreversible steric jamming at the final constriction. Compared with a conventional single-step nanopore, the stepped architecture facilitates high-fidelity observation of unfolding intermediate states at moderate driving forces, thereby avoiding excessive driving conditions that promote kinetic jamming and reduce structural resolution. By establishing a kinetic-competition framework based on native-contact loss, residue-passage timing, and productive axial linearization, this study provides a physical framework for designing blockage-resistant nanopore sensors for high-resolution protein structural analysis.