Nanofluidic system for the studies of single DNA molecules

Abstract

Here, we describe a simple and low-cost lithographic technique to fabricate size-controllable nanopillar arrays inside the microfluidic channels for the studies of single DNA molecules. In this approach, nanosphere lithography has been employed to grow a single layer of well-ordered close-packed colloidal crystals inside the microfluidic channels. The size of the polymeric colloidal nanoparticles could be trimmed by oxygen plasma treatment. These size-trimmed colloidal nanoparticles were then used as the etching mask in a deep etching process. As a result, well-ordered size-controllable nanopillar arrays could be fabricated inside the microfluidic channels. The gap distance between the nanopillars could be tuned between 20 and 80 nm allowing the formation of nanofluidic system where the behavior of a single lambda-phage DNA molecule has been investigated. It was found that the lambda-phage DNA molecule could be fully stretched in the nanofluidic system formed by nanopillars with 50 nm gap distance at a field of 50 V/cm.

Polymeric nanopillar arrays for cell traction force measurements

“…Nanosphere lithography was previously employed to fabricate size-tunable silicon nanopillars in a microfluidic system by Kuo et al [19]. In this experiment, the diameter of nanopillar templates could be tuned by reducing the size of polystyrene beads using cycles of oxygen plasma treatment.…”

“…Polymeric nanopillars can be obtained after curing and mold release. In a previous publication [19], we demonstrated that silicon nanopillar arrays with various diameters can be fabricated inside microfluidic channels, and to fabricate polymeric nanopillar arrays for cell traction force sensing, we modified this fabrication process in the current study. Figure 1 presents a schematic view of the fabrication process.…”

Recent advances in single‐molecule detection on micro‐ and nano‐fluidic devices

“…The sizecontrollable nanopillar arrays inside the microfluidic channels were fabricated by nanosphere lithography. The gap distance between nanopillar could be tuned between 20 and 80 nm allowing the formation of nanofluidic system for single DNA molecule investigation [82]. As narrow as 20 nm channels were created by the Craighead group using the size-reduced electrospun nanofiber method [83].…”

Collision of a long DNA molecule with an isolated nanowire

“…Moreover, a DNA molecule colliding with such a post would be minimally deformed by the channel floor and ceiling that confine the post. While there are experimental data on DNA separations in dense arrays of sub-micron diameter posts [11][12][13][14][15] and DNA collisions with isolated micron-diameter posts [16][17][18], even the most fundamental theoretical predictions [5] about the universal behavior of DNA collisions with a point-sized post remain untested.…”