Electron Transfer in Spacer-Free DNA Duplexes Tethered to Gold via dA10 Tags

Electrical properties of DNA critically depend on the way DNA molecules are integrated within the electronics, particularly on DNA-electrode immobilization strategies. Here, we show that the rate of electron transport in DNA duplexes spacer-free tethered to gold via the adenosine terminal region (a...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1999. - 34(2018), 29 vom: 24. Juli, Seite 8472-8479
1. Verfasser: Campos, Rui (VerfasserIn)
Weitere Verfasser: Kékedy-Nagy, László, She, Zhe, Sodhi, Rana, Kraatz, Heinz-Bernhard, Ferapontova, Elena E
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2018
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't
Beschreibung
Zusammenfassung:Electrical properties of DNA critically depend on the way DNA molecules are integrated within the electronics, particularly on DNA-electrode immobilization strategies. Here, we show that the rate of electron transport in DNA duplexes spacer-free tethered to gold via the adenosine terminal region (a dA10 tag) is enhanced compared to the hitherto reported DNA-metal electrode tethering chemistries. The rate of DNA-mediated electron transfer (ET) between the electrode and methylene blue intercalated into the dA10-tagged DNA duplex approached 361 s-1 at a ca. half-monolayer DNA surface coverage ΓDNA (with a linear regression limit of 670 s-1 at ΓDNA → 0), being 2.7-fold enhanced compared to phosphorothioated dA5* tethering (6-fold for the C6-alkanethiol linker representing an additional ET barrier). X-ray photoelectron spectroscopy evidenced dA10 binding to the Au surface via the purine N, whereas dA5* predominantly coordinated to the surface via sulfur atoms of phosphothioates. The latter apparently induces the DNA strand twist in the point of surface attachment affecting the local DNA conformation and, as a result, decreasing the ET rates through the duplex. Thus, a spacer-free DNA coupling to electrodes via dA10 tags thus allows a perspective design of DNA electronic circuits and sensors with advanced electronic properties and no implication from more expensive, synthetic linkers
Beschreibung:Date Completed 26.09.2018
Date Revised 26.09.2018
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.8b01412