Directional Single-Protein Transport Enabled by 2D Material Heterointerfaces in Solid-State Nanopores: Implications for Single-Molecule Sensing

Directional control of biomolecular transport in solid-state nanopores is crucial for replicating the rectification and gating behaviors of biological channels. Here, we report material-dependent directionality in multilayer nanopores formed in SiN x + graphene + hBN and SiN x + graphene + MoS 2 heterostructures using chemically tuned controlled dielectric breakdown. Transport-defined asymmetry emerges across the nanopore population, giving rise to polarity-dependent differences in capture rate and translocation kinetics over more than half a million holo-human serum transferrin (hSTf) protein events. Single-molecule analysis combined with electrostatic simulations indicates that terminal-layer composition and layer order modulate the local electric field distribution, leading to orientation-dependent transport kinetics. These results highlight that heterointerface engineering in multilayer nanopores can encode transport polarity at the single-molecule level, providing a materials-based strategy to regulate protein translocation dynamics and enhance signal separability for nanopore-based protein sensing.