1,362 research outputs found
Functionalized nanopore-embedded electrodes for rapid DNA sequencing
The determination of a patient's DNA sequence can, in principle, reveal an
increased risk to fall ill with particular diseases [1,2] and help to design
"personalized medicine" [3]. Moreover, statistical studies and comparison of
genomes [4] of a large number of individuals are crucial for the analysis of
mutations [5] and hereditary diseases, paving the way to preventive medicine
[6]. DNA sequencing is, however, currently still a vastly time-consuming and
very expensive task [4], consisting of pre-processing steps, the actual
sequencing using the Sanger method, and post-processing in the form of data
analysis [7]. Here we propose a new approach that relies on functionalized
nanopore-embedded electrodes to achieve an unambiguous distinction of the four
nucleic acid bases in the DNA sequencing process. This represents a significant
improvement over previously studied designs [8,9] which cannot reliably
distinguish all four bases of DNA. The transport properties of the setup
investigated by us, employing state-of-the-art density functional theory
together with the non-equilibrium Green's Function method, leads to current
responses that differ by at least one order of magnitude for different bases
and can thus provide a much more robust read-out of the base sequence. The
implementation of our proposed setup could thus lead to a viable protocol for
rapid DNA sequencing with significant consequences for the future of genome
related research in particular and health care in general.Comment: 12 pages, 5 figure
Colloquium: Physical approaches to DNA sequencing and detection
With the continued improvement of sequencing technologies, the prospect of genome-based medicine is now at the forefront of scientific research. To realize this potential, however, a revolutionary sequencing method is needed for the cost-effective and rapid interrogation of individual genomes. This capability is likely to be provided by a physical approach to probing DNA at the single-nucleotide level. This is in sharp contrast to current techniques and instruments that probe (through chemical elongation, electrophoresis, and optical detection) length differences and terminating bases of strands of DNA. Several physical approaches to DNA detection have the potential to deliver fast and low-cost sequencing. Central to these approaches is the concept of nanochannels or nanopores, which allow for the spatial confinement of DNA molecules. In addition to their possible impact in medicine and biology, the methods offer ideal test beds to study open scientific issues and challenges in the relatively unexplored area at the interface between solids, liquids, and biomolecules at the nanometer length scale. This Colloquium emphasizes the physics behind these methods and ideas, critically describes their advantages and drawbacks, and discusses future research opportunities in the field
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