Controlling Molecular Transport through Nanopores by Dynamic Aperture Sizing

Molecular transport through a nanopore determines the information that can be recovered from a translocation signal, yet it remains difficult to control in conventional solid-state nanopores. Rapid translocation reduces the information content and fixed nanopore geometries limit the dimensionality of the signal. Here, we control molecular transport through the development of the pipette-elastomer interfacial nanopore (PEIN), a dynamically reconfigurable solid-state nanopore which addresses these limitations. A PEIN is formed by depressing a glass nanopipette into a soft elastomer, progressively constricting its aperture and enabling continuous control over aperture size, while retaining the simplicity and favourable noise characteristics of glass nanopipette sensing. Using the dynamic aperture size control, DNA velocities could be controlled over more than a twofold range, with dwell times two orders of magnitude greater than observed in glass nanopipettes. DNA-origami rulers further revealed a progressive reduction in polymer velocity during translocation, indicating that hydrodynamic drag alone is insufficient to model forces on the DNA polymer. Finally, by using single- and double-stranded DNA and gold nanoparticles as molecular standards, we demonstrate reversible, size-selective molecular gating with sub-nanometre control. These results establish the PEIN as an accessible platform for controlling molecular transport and probing the relationships among biopolymer conformation, nanoscale confinement and translocation dynamics.