| 1. |
- Kang, Yu, et al.
(författare)
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Na+ and K+ ion selectivity by size-controlled biomimetic graphene nanopores
- 2014
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 6:18, s. 10666-10672
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Tidskriftsartikel (refereegranskat)abstract
- Because biological ionic channels play a key role in cellular transport phenomena, they have attracted extensive research interest for the design of biomimetic nanopores with high permeability and selectivity in a variety of technical applications. Inspired by the structure of K+ channel proteins, we designed a series of oxygen doped graphene nanopores of different sizes by molecular dynamics simulations to discriminate between K+ and Na+ channel transport. The results from free energy calculations indicate that the ion selectivity of such biomimetic graphene nanopores can be simply controlled by the size of the nanopore; compared to K+, the smaller radius of Na+ leads to a significantly higher free energy barrier in the nanopore of a certain size. Our results suggest that graphene nanopores with a distance of about 3.9 A between two neighboring oxygen atoms could constitute a promising candidate to obtain excellent ion selectivity for Na+ and K+ ions.
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| 2. |
- Kang, Yu, et al.
(författare)
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On the Mechanism of Protein Adsorption onto Hydroxylated and Nonhydroxylated TiO2 Surfaces
- 2010
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Ingår i: The Journal of Physical Chemistry C. - Washington DC, USA : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:34, s. 14496-14502
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Tidskriftsartikel (refereegranskat)abstract
- Protein adsorption onto implant surfaces is of great importance for the regulation of implant bioactivity. Surface modification of implants is a promising way in the molecular design of biocompatible materials against nonspecific adsorption of proteins. On the basis of these fundamental facts, we focus in this work on the different behavior of protein adsorption on hydroxylated and nonhydroxylated rutile TiO2 (110) surfaces through molecular dynamics simulations. Our investigation indicates that the distribution of the water molecules at the interface induced by the surface modification plays an important role in the protein adsorption. The surface with modified hydroxyl groups was observed to have much greater affinity to the protein, as reflected by the larger protein-surface electrostatic interaction and by the larger amount of adsorbed residues. The highly ordered structure of the modified hydroxyl groups on the hydroxylated surface diminishes the possibility of hydrogen bond formation between the surface and the water molecules above it, which in turn makes it easier for the protein to move closer to the surface with hydroxyl modification.
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