Assembly of a Noncovalent DNA junction on graphene sheets and electron transport characteristics

摘要

Single-stranded (ss) DNA readily absorbs on graphene nanoribons (GNR) due to van der Waals interactions. Such absorption can be used for a single ssDNA characterization, enabling potential applications in biotechnology as well as in chemical and biological sensing. We analyze, using molecular dynamics simulations, the attachment process of the DNA codon GAG drifted by an external electric field on a gapped graphene nanoribbon. We calculate the quantum electron transport through a noncovalent junction GNR-DNA surrounded by a water monolayer with sodium counterions. We find that the GNR-DNA junction is stable in aqueous conditions at room temperature and at 330K. The DNA molecule causes a smooth transition to the conductive state of the gapped graphene; we estimate a detectable electronic signal of ∼2 nA, which allows us to identify the DNA molecule bridging the gapped graphene.

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