Prolonged DNA Translocation through Graphene-Coupled Si₃N₄ Dual Nanopores

Nanopore technology holds immense promise for DNA sensing and sequencing, offering the potential for ultralong read lengths and real-time detection without amplification. However, the rapid translocation of DNA through these pores severely limits signal resolution and sensing accuracy. In this work, we present a novel device architecture that synergistically integrates a dual-nanopore structure with a graphene interface to achieve prolonged DNA transport in a controllable and reproducible manner. We observe a characteristic cocapture mode in the dual-pore systems that extends dwell times by approximately an order of magnitude compared to single-pore events. By transferring a graphene film onto Si₃N₄ dual-pore systems, we fabricated a graphene-coupled Si₃N₄ dual-nanopore device and achieved a substantial further increase in the cocaptured translocation time. Molecular dynamics simulations elucidate the underlying mechanism: the graphene layer modulates the axial potential inside the nanopore, inducing a more gradual drop and consequently attenuating the effective electric field gradient in the cocapture region. Concurrently, strong van der Waals and π-π interactions between the graphene surface and DNA significantly enhance interfacial adhesion. The combination of geometric tug-of-war and interfacial adsorption effects synergistically decelerates the cocaptured DNA translocation. These findings enable fine-tuned control over DNA translocation dynamics without sacrificing the signal-to-noise ratio, laying a foundation for constructing next-generation solid-state nanopore platforms with high resolution and high fidelity.