Comparing Charge Transport in Oligonucleotides: RNA:DNA Hybrids and DNA Duplexes

详细信息    查看全文

• 作者：Yuanhui Li ; Juan M. Artés ; Jianqing Qi ; Ian A. Morelan ; Paul Feldstein ; M. P. Anantram ; Joshua Hihath
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2016
• 出版时间：May 19, 2016
• 年：2016
• 卷：7
• 期：10
• 页码：1888-1894
• 全文大小：603K
• 年卷期：0
• ISSN：1948-7185

文摘

Understanding the electronic properties of oligonucleotide systems is important for applications in nanotechnology, biology, and sensing systems. Here the charge-transport properties of guanine-rich RNA:DNA hybrids are compared to double-stranded DNA (dsDNA) duplexes with identical sequences. The conductance of the RNA:DNA hybrids is ∼10 times higher than the equivalent dsDNA, and conformational differences are determined to be the primary reason for this difference. The conductance of the RNA:DNA hybrids is also found to decrease more rapidly than dsDNA when the length is increased. Ab initio electronic structure and Green’s function-based density of states calculations demonstrate that these differences arise because the energy levels are more spatially distributed in the RNA:DNA hybrid but that the number of accessible hopping sites is smaller. These combination results indicate that a simple hopping model that treats each individual guanine as a hopping site is insufficient to explain both a higher conductance and β value for RNA:DNA hybrids, and larger delocalization lengths must be considered.