Effect of Graphene Oxidation Rate on Adsorption of Poly‐Thymine Single Stranded DNA. Issue 8 (21st March 2017)

• Record Type: Journal Article
• Authors: Kim, Ho Shin; Farmer, Barry L.; Yingling, Yaroslava G.
• Is Part Of: Advanced materials interfaces. Volume 4:Issue 8(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-03-21
• Subjects: DNA -- graphene -- molecular dynamics simulations -- physisorption -- surface oxidation; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.201601168
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract : In order to understand how oxidation rate of graphene surfaces affects single‐stranded poly‐thymine, poly(T)20, structure during physisorption, all‐atom molecular dynamics simulations are performed. In aqueous solutions, poly(T)20 is a complex structure with stacked and coiled regions. However, on the graphene surfaces, there are three different regimes for the adsorption process, which heavily depends on the surface oxidation: (1) on pristine graphene or graphene oxide (GO) with low oxygen coverage (GO 5%) the stacked poly(T)20 structure becomes unfolded due to formation of strong π–π interactions with the surface, (2) on graphene oxide with moderate oxygen coverage (GO 10%–25%) the structure of poly(T)20 is well preserved because of the balance between van der Waals and electrostatic interactions, and (3) on graphene oxide with high oxygen content (GO 30%–60%) stacked poly(T)20 structure is locally disrupted due to formation of strong hydrogen bonds with the surface. Moreover, surface roughness due to the presence of oxygen groups plays a pivotal role in structural retention of poly(T)20 by preventing its nucleobases from forming π–π stacking interactions with the surface. Abstract : Representative snapshots illustrating how surface oxidation rate can affect conformational changes of prefolded poly(T)20 on graphene surfaces. In the case of the surface with low or high oxidation rate, strong van der Waals or electrostatic interactions make poly(T)20 unstable. However, on graphene oxide with moderate oxidation rate, poly(T)20 has a good structural retention due to balanced nonbonded interactions.