Electronic Signatures of all Four DNA Nucleosides in a Tunneling Gap

• Published in: Nano letters Vol. 10; no. 3; pp. 1070 - 1075
• Main Authors: Chang, Shuai, Huang, Shuo, He, Jin, Liang, Feng, Zhang, Peiming, Li, Shengqing, Chen, Xiang, Sankey, Otto, Lindsay, Stuart
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 10.03.2010
• Subjects: Computer Simulation; Condensed matter: electronic structure, electrical, magnetic, and optical properties; DNA - chemistry; Electron states; Electron Transport; Exact sciences and technology; Letter; Methods of electronic structure calculations; Models, Chemical; Nucleosides - chemistry; Physics; Semiconductors; hydrogen bonding; molecular recognition; electron tunneling; DNA nucleosides; DNA sequencing; Hydrogen bonds; DNA; Tunnel effect; Density functional method; Nucleosides; Contact resistance; Gallium phosphide
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl1001185

Nucleosides diffusing through a 2 nm electron-tunneling junction generate current spikes of sub-millisecond duration with a broad distribution of peak currents. This distribution narrows 10-fold when one of the electrodes is functionalized with a reagent that traps nucleosides in a specific orientation with hydrogen bonds. Functionalizing the second electrode reduces contact resistance to the nucleosides, allowing them to be identified via their peak currents according to deoxyadenosine > deoxycytidine > deoxyguanosine > thymidine, in agreement with the order predicted by a density functional calculation.