Electronic signatures of all four DNA nucleosides in a tunneling gap.
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.
Chang
Shuai
S
Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.
Huang
Shuo
S
He
Jin
J
Liang
Feng
F
Zhang
Peiming
P
Li
Shengqing
S
Chen
Xiang
X
Sankey
Otto
O
Lindsay
Stuart
S
D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D004579:Electron Transport; D008956:Models, Chemical; D009705:Nucleosides / Q000737:chemistry*; D012666:Semiconductors
D009705:Nucleosides; D004247:DNA