Polydopamine-modified nanocrystalline diamond thin films as a platform for bio-sensing applications

• Published in: Thin solid films 2013-09, Vol.543, p.180-186
• Main Authors: Pop-Georgievski, Ognen, Neykova, Neda, Proks, Vladimir, Houdkova, Jana, Ukraintsev, Egor, Zemek, Josef, Kromka, Alexander, Rypaček, František
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Deposition; Diamonds; Dopamine; Electron, ion, and scanning probe microscopy; Exact sciences and technology; Nanocrystalline diamond films; Nanocrystals; NCD; PDA; Physics; Platforms; Polydopamine; Polymerization; Scanning probe microscopy: scanning tunneling, atomic force, scanning optical, magnetic force, etc; Solid-fluid interfaces; Structure of solids and liquids; crystallography; Surface modification; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin films; Wetting
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2012.11.128

Diamond exhibits good biocompatibility and a large electrochemical potential window, and thus, it is particularly suitable for bio-functionalization and bio-sensing. Modification of the diamond surface can be achieved through mussel-inspired surface chemistry based on polydopamine (PDA) while maintaining the intrinsic properties of the surface. We present a comparative study on the polymerization/deposition of PDA from an aqueous solution of dopamine on hydrogen- (H) and oxygen- (O) terminated nanocrystalline diamond films (NCD). The dopamine polymerization/deposition was performed under mild conditions, which resulted in a confluent PDA layer. A detailed investigation of the growth kinetics of the PDA film on H- and O-terminated NCD substrates was performed using spectroscopic ellipsometry. The chemical composition, the functional group distribution, the surface topography and the wetting properties of the adherent PDA films were evaluated using X-ray photoelectron spectroscopy, atomic force microscopy and water contact angle goniometry, respectively. According to the results, a PDA layer can be used as a platform for future bio-functionalization and/or optical bio-sensing applications. ► Nanocrystalline diamond (NCD) was modified through polydopamine (PDA) chemistry. ► PDA's growth kinetics on H- and O-terminated NCD films were investigated. ► The growth kinetics and composition of PDA were independent of the NCD termination.