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Direct measurement of electrical transport through G-quadruplex DNA with mechanically controllable break junction electrodes.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Liu, Shou‐ Peng Weisbrod, Samuel H. Tang, Zhuo Marx, Andreas Scheer, Elke Erbe, Artur |
| Copyright Year | 2010 |
| Abstract | The need for miniaturization of devices for future nanoelectronic applications has led to the search for new constituents in molecular electronics. DNA is particularly interesting for applications in nanoelectronics circuits owing to its inherent properties, such as the predictable size and selfassembly of the stacked nucleobase pairs. 2] In recent years, charge transport in double-stranded DNA (dsDNA) has attracted considerable attention because of its potential use in building blocks for future nanoelectronic circuits. The onedimensional nanowire conformation of DNA and its unique self-assembly ability 2] can also be used in biochemical sensors. Theoretical studies suggested rather high conductance of DNA in the case of optimal and undisturbed overlap of the electronic orbitals of the p electrons. Previously, several experimental groups reported high conductance of particular DNA molecules, whereas other experiments showed predominantly that the conductance of DNA was very low, which is presumably due to variation in the contact geometries 12] and its variable sequence and flexible conformation. However, it was recently reported that short dsDNA with a G–C sequence is more conductive than that with a A–T sequence. Certain guanine-rich DNA sequences, such as those found in telomeres at the end of chromosomes, can form stable four-stranded structures, which result from the stacking of several G-quartets folding into quadruplex structures. Furthermore, potential G-quartet-forming sequences have been found to be enriched in promoters of proto-oncogenes. Herein we present direct transport measurements on a G-quadruplex covalently wired between two gold electrodes realized by the mechanically controllable break junction (MCBJ) technique. The G-quadruplex shows a rather high conductance. Interestingly, when the distance of both electrodes was reversibly varied over a several-nanometer span, this conductance behavior persists reproducibly. These unprecedented properties make G-quadruplexes interesting candidates for nanoelectronic applications in which varied distances between electrodes need bridging without loss of conductance. Apart from the usual helical double-stranded form, DNA with particular sequences can also form stable four-stranded structures with repeated guanine bases. These structures result from the stacking of several G-quartets (planes of four guanines held together by eight hydrogen bonds; Figure 1a). The G-quartet stacking can be further stabilized by cations (typically K or Na) located between two quartets. From various sequences, both intramolecular and intermolecular G-quadruplexes or G-wires with lengths of up to micrometers can be formed. For the human telomeric sequence that was used in our experiments, different structures are reported that containing either parallel, antiparallel, or even mixed parallel-antiparallel folding of the strands. |
| File Format | PDF HTM / HTML |
| DOI | 10.1002/anie.201000022 |
| PubMed reference number | 20349484 |
| Journal | Medline |
| Volume Number | 49 |
| Issue Number | 19 |
| Alternate Webpage(s) | https://kops.uni-konstanz.de/bitstream/handle/123456789/5326/2010_Erbe_Angewandte_Chemie_International_Edition_49_3313_.pdf?isAllowed=y&sequence=1 |
| Alternate Webpage(s) | https://doi.org/10.1002/anie.201000022 |
| Journal | Angewandte Chemie |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
