Comparison of Canonical versus Silver(I)-Mediated Base-Pairing on Single Molecule Conductance in Polycytosine dsDNA

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• 作者：Emily Toomey ; Jimmy Xu ; Simon Vecchioni ; Lynn Rothschild ; Shalom Wind ; Gustavo E. Fernandes
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：April 14, 2016
• 年：2016
• 卷：120
• 期：14
• 页码：7804-7809
• 全文大小：298K
• 年卷期：0
• ISSN：1932-7455

文摘

Intercalation of metal ions into double-stranded DNA has recently been proposed as a path to efficient charge transport in DNA wires. Until now, the effect of Ag(I) intercalation between mismatched cytosine nucleobases on the conductance of DNA has not been assessed. Here we use a scanning tunneling microscopy (STM) break-junction technique to evaluate and compare the single molecule conductance of polynucleotide sequences of 11 base pairs in length. The resulting single molecule conductance for Ag(I)–polyC is found to be an order of magnitude greater than the control strand made using canonical Watson–Crick pairing. This finding suggests that Ag(I) intercalation alters the dominant electron transport process from standard π-orbital delocalization common in sequences with multiple stacked guanines to an alternate and ultimately more efficient conduit.