Ion current rectification inversion is observed in a funnel-shaped nanochannel above a threshold voltage roughly corresponding to the under-limiting to over-limiting current transition. Previous experimental studies have examined rectification at either low-voltages (under-limiting current region) for conical nanopores/funnel-shaped nanochannels or at high-voltages (over-limiting region) for st...

While notable progress has been made in recent years both experimentally and theoretically understanding the highly complex dynamics of polymer capture transport through nanopores, there remains significant disagreement between experimental observation theoretical prediction that needs to be resolved. Asymmetric salt concentrations, where concentrations ions on each side membrane are different,...

We show a simple, robust, chemical route to the fabrication of ultrahigh-density arrays of nanopores with high aspect ratios using the equilibrium self-assembled morphology of asymmetric diblock copolymers. The dimensions and lateral density of the array are determined by segmental interactions and the copolymer molecular weight. Through direct current electrodeposition, we fabricated vertical ...

Nanoporous redox cycling devices are highly efficient tools for the electrochemical sensing of redox-active molecules. By using a redox-active mediator, this concept can be exploited for the detection of molecular binding events via blocking of the redox cycling current within the nanopores. Here, we investigate the influence of different blocking scenarios inside a nanopore on the resulting re...

Thermal rectification is a fundamental phenomenon for active heat flow control. Significant thermal rectification is expected to exist in the asymmetric nanostructures, such as nanowires and thin films. As a one-atom-thick membrane, graphene has attracted much attention for realizing thermal rectification as shown by many molecular dynamics simulations. Here, we experimentally demonstrate therm...

By combining low-energy ion irradiation with asymmetric etching, conical nanopores of controlled geometry can be etched in polycarbonate (PC). Cone bases vary from 0.5 to 1μm. Top diameters down to 17 nm are reached.. When etching from one side, the pH on the other side (bathed in neutral or acidic buffer) was monitored. Etching temperature ranged from 65°C to 80°C. Pore shape characterization ...

Nanopores are extremely sensitive single-molecule sensors. Recently, electron beams have been used to fabricate synthetic nanopores in thin solid-state membranes with subnanometer resolution. Here we report a new class of chemically modified nanopore sensors. We describe two approaches for monolayer coating of nanopores: (1) self-assembly from solution, in which nanopores approximately 10 nm di...

Abstract Single- and multilayer graphene sheets (MLGSs) are projectile-resisting materials that can be bombarded by nanoparticles to produce graphene sheets of various sizes and distributions of nanopores. These sheets are used in a variety of applications, including DNA sequencing, water desalination, and phase separation. Here, the impact-withstanding efficiency of graphene nanosheets and the...

Determining water structure in nanopores and its influence on water transport behaviour is of great importance for understanding and regulating the transport across nanopores. Here we report an ultrafast-slow flow transition phenomenon for water transport across nanopores of carbon nanotubes owing to the change in water structure in nanopores induced by temperature. By performing extensive mole...