Scientific collaborators at University of Rochester and University of Ottawa have developed a new DNA reader based nanopores that can accurately identify the nucleotides passing through. It consists of a silicon nitride membrane, that has nano-sized pores within its body, and a biosensor membrane with only one nanopore. The two membranes are positioned 200 nanometers apart, and as a sample containing DNA is introduced, the DNA molecules are allowed to pass through the multi-pore membrane while most other things are not. The DNA molecules that pass through the initial membrane and that manage to get into the single-pore membrane end up being stretched out and elongated, which facilitates the detection of the individual nucleotides. As the molecule moves through, a change in the electric current delivered through the device can be detected as each nucleotide passes the single nanopore.
This animation shows, as U of Rochester graduate student Greg Madejski explains, the “thin films of water, seen as rainbow colors, swelling and shrinking the space between the prefilter and the nanopore as its exposed to additional water vapor.”
The technology was actually the result of some good luck, as attaching the two nanopore membranes proved a challenge. Greg Madejski, a graduate student at James McGrath’s lab at the University of Rochester, was frustrated trying to stick the membranes together under the microscope and accidentally exhaled on them in exasperation. Miraculously, the two stuck together perfectly because the humid air of his breath was just the thing that was required.
The technology still has to be parallelized and sped up to really prove itself in practice, but there’s already evidence that this technology has great potential. For example, the device is less likely to clog than other silicon nanopore-based devices and will last longer than biological membranes.
Study in Nano Letters: DNA Translocations through Nanopores under Nanoscale Preconfinement…
