Transverse tunneling through DNA hydrogen bonded to an electrode.
Guanidinium ions tethered to an electrode form electrical contacts to DNA via hydrogen bonding with the backbone phosphates, thus providing a sequence-independent electrical connector for native DNA submerged in an aqueous electrolyte. DNA adlayers on a guanidinium modified electrode can be imaged by scanning tunneling microscopy with tens of pS gap conductance. The image resolution suggests that multiatom contacts contribute to the tunnel conductance, so we estimate that the single-nucleotide pair conductance may be on the order of 1 pS.
He
Jin
J
Biodesign Institute, Arizona State University, Tempe, Arizona 85287, USA.
Lin
Lisha
L
Zhang
Peiming
P
Spadola
Quinn
Q
Xi
Zhiqun
Z
Fu
Qiang
Q
Lindsay
Stuart
S
D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure*; D004566:Electrodes; D019791:Guanidine / Q000737:chemistry; D006860:Hydrogen Bonding; D018625:Microscopy, Atomic Force; D016252:Microscopy, Scanning Tunneling
D004247:DNA; D019791:Guanidine