Charge Transport in a Multiterminal DNA Tetrahedron: Interplay among Contact Position, Disorder, and Base-Pair Mismatch
Abstract
As a secondary structure of DNA, DNA tetrahedra exhibit intriguing charge-transport phenomena and provide a promising platform for wide applications like biosensors, as shown in recent electrochemical experiments. Here, we study charge transport in a multiterminal DNA tetrahedron, finding that its charge-transport properties strongly depend upon the interplay of contact position, on-site energy disorder, and base-pair mismatch. Our results indicate that this multiterminal DNA tetrahedron behaves as a nanoscale charge splitter when the source is contacted at the top vertex. Besides, we find that the charge-transport efficiency is nearly independent of the contact position in the weak disorder regime, and is dramatically declined by the occurrence of a single base-pair mismatch between the source and the drain, in accordance with experimental results [J. Am. Chem. Soc. 134, 13148 (2012); Chem. Sci. 9, 979 (2018)]. By contrast, the charge-transport efficiency will be enhanced monotonically by shifting the source toward the drain in the strong disorder regime, and be increased when the base-pair mismatch takes place exactly at the contact position. In particular, when the source moves successively from the top vertex to the drain, the charge transport through the tetrahedral DNA device can be separated into three regimes, ranging from disorder-induced linear decrement of conductance to disorder-insensitive charge transport, and to disorder-enhanced charge transport. Finally, we predict that the DNA tetrahedron functions as a more efficient spin filter compared to double-stranded DNA and as a nanoscale spin splitter with opposite spin polarization observed at different drains. These results could be readily checked by electrochemical measurements and help for designing intriguing DNA tetrahedron-based molecular nanodevices.
- Publication:
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Physical Review Applied
- Pub Date:
- February 2022
- DOI:
- 10.1103/PhysRevApplied.17.024074
- arXiv:
- arXiv:2107.10411
- Bibcode:
- 2022PhRvP..17b4074H
- Keywords:
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- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Soft Condensed Matter
- E-Print:
- Comments are welcome