Self-assembled Nanowire Arrays as Three-dimensional Nanopores for Filtration of DNA Molecules

Abstract

Molecular filtration and purification play important roles for biomolecule analysis. However, it is still necessary to improve efficiency and reduce the filtration time. Here, we show self-assembled nanowire arrays as three-dimensional (3D) nanopores embedded in a microfluidic channel for ultrafast DNA filtration. The 3D nanopore structure was formed by a vapor-liquid-solid (VLS) nanowire growth technique, which allowed us to control pore size of the filtration material by varying the number of growth cycles. λ DNA molecules (48.5 kbp) were filtrated from a mixture of T4 DNA (166 kbp) at the entrance of the 3D nanopore structure within 1 s under an applied electric field. Moreover, we observed single DNA molecule migration of T4 and λ DNA molecules to clarify the filtration mechanism. The 3D nanopore structure has simplicity of fabrication, flexibility of pore size control and reusability for biomolecule filtration. Consequently it is an excellent material for biomolecular filtration.

Fabrication of nanoporous membranes for tuning microbial interactions and biochemical reactions

“…Silicon dioxide was deposited with an Oxford Instruments Plasmalab System 100 PECVD (Abington, Oxfordshire, UK) tool (RF 20 W, 5%SiH 4 C precursor: bis (diethylamino)silane time 0.7 s] with a deposition rate of 3 Å /cycle was used for 27 cycles to further decrease the pore size by 8 nm and tune the MWCO of the nanomembrane. After the bioreactor fabrication was complete, the devices were sealed by air plasma bonding with a Harrick Plasma PDC-001 air plasma cleaner (Ithaca, NY) a 5 mm thick PDMS cover over the device.…”

“…Such membranes have been made using self-assembled nanowires, 4 colloidal selfassemblies, 5 amorphous silicon (a-Si) to porous nanocrystalline silicon (pnc_Si) crystallization, 6 and vertically aligned carbon nanofibers. [7][8][9][10][11] These membranes still rely on restricting transport with implementation of tortuous paths that molecules must take to pass through the membrane.…”

Oxide nanowire microfluidics addressing previously-unattainable analytical methods for biomolecules towards liquid biopsy

“…To improve the resolution for DNA separation with the device, we have developed 3D nanowire arrays for ultra-fast separation of biomolecules. [79][80][81] In our latest work, by advancing the self-assembling formation technology of nanowires, we fabricated branching nanowire structures and developed the world's first 3D nanowire arrays that can be spatially controlled to a level of a few nanometers at targeted locations in microchannels. The proposed methodology for controlling the pore size of the 3D nanowire arrays was varying the number of nanowire growth cycles (Fig.…”

“…7), 81 which allows us to obtain nanowires sized as thin as the hydrodynamic radius of protein and RNA molecules. 80 Using this technique, we have achieved fast separation of not only DNA but also RNA and proteins with molecular weights smaller than DNA within a few seconds to a few tens of seconds.…”

Nanostructures Integrated with a Nanochannel for Slowing Down DNA Translocation Velocity for Nanopore Sequencing

“…Recently, nanostructures have been integrated with micronanodevices to achieve faster nanopore DNA sequencing. 3,4 In this work, we attempted to slow down DNA velocity in a nanochannel, which is a simulant structure of a nanopore, by combining nanometer-scale shallow channel and nanopillar array. Because these nanostructures can increase the electric resistance in the area and thus the electric field in the nanochannel located in close vicinity is decreased, we expected to slow down DNA in the nanochannel.…”