Direct conductance measurements of short single DNA molecules in dry conditions.
We present a study of electronic transport in short (12-base-pair) DNA duplexes covalently bonded (via thiol groups) to two gold electrodes obtained by a mechanically controllable break junction (MCJB) technique in dry conditions. A large number of DNA junctions have been repeatedly formed in order to obtain a conductance histogram that reveals a peak which corresponds to the conductance of a single DNA molecule. We observed that the conductivity of a DNA increases upon increasing the content of G:C base pairs in the duplex. With our method we are able to obtain a reliable value of a single DNA conductance and subsequently measure its current-voltage (I-V) characteristics. In contrast to the electronic transport measurements performed with long DNA sequences (hundreds of base pairs) where the obtained conductance values vary a lot with environmental conditions, our values obtained for the short DNA sequences are consistent with the values reported for comparable sequences in aqueous solution.
Dulić
Diana
D
Laboratoire d'Electronique Moléculaire, Service de Physique de L'Etat Condensé (CNRS URA 2464), CEA, IRAMIS, F-91191 Gif-sur-Yvette, France. Diana.Dulic@cea.fr
Tuukkanen
Sampo
S
Chung
Chia-Ling
CL
Isambert
Antoine
A
Lavie
Pascal
P
Filoramo
Arianna
A
D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D003890:Desiccation; D004553:Electric Conductivity; D004566:Electrodes; D013997:Time Factors
D004247:DNA