Important structural factors controlling the conductance of DNA pairs in molecular junctions

• It has been demonstrated experimentally that DNA base pairs and sequences can be identified by measuring their current changes in metal junctions. We report here a first principles study on electron transport properties of DNA base pairs in gold metal junctions. It is found that the experimentally observed electrode-separation-width-dependent current changes of DNA base pairs are not due to the difference in number of hydrogen bonds involved in different base pairs as proposed in earlier experimental studies but caused by the difference in their stacking structures. It reveals that such an electronic read-out technique is not exact, but practically useful since the statistically favorable misaligned junctions do show distinct dependence on the character of the base pair. 

Keyword

Base pairs

Current change

DNA base pairs

Experimental studies

First-principles study

Metal junctions

Molecular junction

Stacking structures

Structural factor

Publication and Content Type

ref (subject category)

art (subject category)