Plasma amination of ultrananocrystalline diamond/amorphous carbon composite films for the attachment of biomolecules

• Published in: Diamond and related materials Vol. 20; no. 2; pp. 254 - 258
• Main Authors: Koch, H., Kulisch, W., Popov, C., Merz, R., Merz, B., Reithmaier, J.P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2011; Elsevier
• Subjects: Attachment; Biomolecules; Biosensors; Carbon; Chemical vapor deposition; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Contact angle; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fluorescence Microscopy; Ion and electron beam-assisted deposition; ion plating; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanostructure; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma applications; Plasma-based ion implantation and deposition; Structure and morphology; thickness; Surface Characterization; Surface Functionalization; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Ultrananocrystalline Diamond; X-ray Photoelectron Spectroscopy; Surface Characterization; X-ray Photoelectron Spectroscopy; Ultrananocrystalline Diamond; Fluorescence Microscopy; Surface Functionalization; Methane; Amorphous thin film; Thiols; Esters; Contact angle; Surface analysis; Surface structure; Thin films; CVD; Ammonia; Ultrananocrystalline diamond; Composite materials; Functionalization; Nanocomposites; Organic molecule; Fluorescein; Biosensors; Microwave discharge; Plasma deposition; Fluorescence microscopy; X-ray photoelectron spectra
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2010.12.010

Ultrananocrystalline diamond/amorphous carbon nanocomposite films (UNCD/a-C) have been deposited by microwave plasma chemical vapour deposition at 600 °C from 17% CH 4/N 2 mixtures. The as-grown films turned out to be hydrogen terminated and very stable. Photochemical amination of H-terminated diamond is a well-established route to attach functional groups to such surfaces for applications in biosensors. Here we report on experiments to aminate UNCD surfaces directly by exposure to ammonia plasmas. Thereafter the surfaces were reacted with the heterobifunctional crosslinker molecule SSMCC bearing a N-hydroxysuccinimide (NHS) ester group which should react with the surface NH 2 groups. By means of X-ray photoelectron spectroscopy (XPS), contact angle measurements and fluorescence microscopy it is shown that both steps, plasma amination and SSMCC attachment lead to the desired aims. On the other hand, experiments to attach a thiol-bearing fluorescein molecule directly to H-terminated UNCD films turned out to be partially successful although according to literature such a reaction should be very unlikely. ► plasma amination of ultrananocrystalline diamond/amorphous carbon composite films. ► modification of wettability and surface termination. ► direct attachment of crosslinker and thiol-bearing fluorescein.