Clog-free translocation of long DNA in nanofluidic pillar arrays and 30 nm wide channels: A fabrication and hydrodynamic study

We fabricate nanofluidic devices, comprising diamond-shaped nanopillars and nanochannels as narrow as 30 nm using photolithographic techniques, and demonstrate successful translocation of long 1DNA (48.5 kbp) and T4 DNA (166 kbp) through these nanostructures. λ-DNA molecules can transit through 10 μm-long nanochannels in ∼50 ± 10 msec at ∼210 μm/sec without clogging, due to prestretching of the DNA molecules that results from geometrical confinement and straddling of the molecules around the nano-pillars. λ-DNA translocation speed can be linearly tuned from ∼300 to ∼900 μm/sec by electrophoresis with a mobility of (1.3 ± 0.15) × 10^-4 cm²/(V · sec). Importantly, T4 DNA molecules translocated through channels as small as 30 nm, extending their length to 73.5 μm in the process, i.e. ∼100 % of its dyed contour length.