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Effect of surface structure and wettability of DLC and N-DLC thin films on adsorption of glycine

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Ahmed, M and Byrne, JA (2012) Effect of surface structure and wettability of DLC and N-DLC thin films on adsorption of glycine. Applied Surface Science, 258 (12). p. 5166. [Journal article]

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URL: http://dx.doi.org/10.1016/j.apsusc.2012.01.162

DOI: 10.1016/j.apsusc.2012.01.162

Abstract

Diamond-like carbon (DLC) is known to have excellent biocompatibility. Various samples of DLC and nitrogen-doped DLC thin films (N-DLC) were deposited onto silicon substrates using plasma-enhanced chemical vapour deposition (PECVD). Subsequently, the adsorption of amino acid glycine onto the surfaces of the thin films was investigated to elucidate the mechanisms involved in protein adhesion. The physicochemical characteristics of the surfaces, before and after adsorption of glycine, were investigated using Fourier transfer infrared (FTIR), Raman spectroscopy, spectroscopic ellipsometry (SE) and contact angle (). The Raman study highlighted decrease slightly in the ID/IG ratio at low levels of N (5.4 at.%), whilst increasing the nitrogen dopant level (>5.4 at.%) resulted in a increase of the ID/IG ratio, and the FTIR band at related to C N. Following exposure to glycine solutions, the presence of Raman bands at 1727 cm−1 and 1200 cm−1, and FTIR bands at 1735 cm−1 indicates that the adsorption of glycine onto the surfaces has taken place. These results which obtained from SE and surface free energy, show that low levels of nitrogen doping in DLC enhances the adsorption of the amino acid, while, increased doping ledto a reduced adsorption, as compared to undoped DLC. Glycine is bound to the surface of the DLC films via both de-protonated carboxyl and protonated amino groups while, in the case of N-DLC gylcine was bound to the surface via anionic carboxyl groups and the amino group did not interact strongly with the surface. Doping of DLC may allow control of protein adsorption to the surface.© 2012 Elsevier B.V. All rights reserved.

Item Type:Journal article
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Engineering
Research Institutes and Groups:Engineering Research Institute
Engineering Research Institute > Nanotechnology & Integrated BioEngineering Centre (NIBEC)
ID Code:21670
Deposited By:Professor John Byrne
Deposited On:02 Apr 2012 09:37
Last Modified:07 Apr 2014 09:50

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