Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 53: Nanostructures at Surfaces: Other Aspects
O 53.8: Poster
Dienstag, 21. März 2017, 18:30–20:30, P1C
Universal readers based on hydrogen bonding or π-π stacking for identification of DNA nucleotides in electron tunnel junctions — •Suman Sen1, JongOne Im2, Peiming Zhang2, and Stuart Lindsay2 — 1Max Planck Institute, Stuttgart, Germany — 2Arizona State University, Tempe, USA
A universal reader molecule, which recognizes all the naturally occurring nucleobases in a tunnel junction, is required for sequencing DNA by a recognition tunneling (RT) technique. We have designed a series of heterocyclic carboxamides based on hydrogen bonding and a large-sized pyrene ring based on a π-π stacking interaction as reader candidates. RT measurements were carried out in a scanning tunnel microscope. All of these molecules generated electrical signals with DNA nucleotides in tunneling junctions under physiological conditions. Using a support vector machine as a tool for data analysis, we found that these candidates distinguished among naturally occurring DNA nucleotides with the accuracy of pyrene > azole carboxamides. In addition, the pyrene reader operated efficiently in a larger tunnel junction. However, the azole carboxamide could read abasic monophosphate, a product from spontaneous base hydrolysis or an intermediate of base excision repair. Thus, we envision that sequencing DNA using both π-π stacking and hydrogen-bonding-based universal readers in parallel should generate more comprehensive genome sequences than sequencing based on either reader molecule alone.