Comparison on protein adsorption properties of diamond-like carbon and nitrogen-containing plasma polymer surfaces

• Published in: Thin solid films Vol. 520; no. 7; pp. 3021 - 3025
• Main Authors: Yin, Yongbai, Fisher, Keith, Nosworthy, Neil J., Bax, Daniel, Clarke, Ron J., McKenzie, David R., Bilek, Marcela M.M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 31-01-2012; Elsevier
• Subjects: Composition and phase identification; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Diamond-like carbon; Electron paramagnetic resonance; ELISA assay; Enzyme activity; Exact sciences and technology; Fourier Transform Infrared Ellipsometry; Fullerenes and related materials; diamonds, graphite; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Materials science; Optical instruments, equipment and techniques; Physics; Plasma polymerization; Polarimeters and ellipsometers; Protein immobilization; Solid surfaces and solid-solid interfaces; Specific materials; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; X-ray photoelectron spectroscopy; Protein immobilization; Enzyme activity; Diamond-like carbon; Fourier Transform Infrared Ellipsometry; Electron paramagnetic resonance; Plasma polymerization; ELISA assay; X-ray photoelectron spectroscopy; Enzymes; Fourier transform spectroscopy; Pressure effects; Macromolecules; Immobilization; Surface composition; Physical properties; Ellipsometry; Binding protein; Adsorption; Ionic polymerization; Chemical properties; Polymers; X-ray photoelectron spectra
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.11.054

In this paper, the surface and functional protein binding properties of the diamond-like carbon (DLC) and nitrogen-containing plasma polymer (NPP) surfaces were compared using techniques such as X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), enzyme-linked immunosorbent assay (ELISA) and enzyme activity assays. The NPP surfaces were more similar to proteins in respects of their composition and surfaces energies, which are preferred to accommodate immobilized proteins in a more natural manner to retain their bioactivity. The EPR analysis suggested that the radicals in the NPP surfaces could more readily participate in the covalent immobilization of proteins, consistent with the ELISA and XPS analysis result that the NPP surface had approximately double covalent coverage immobilized protein compared with the DLC surface. The enzyme activity assay showed better retention of protein bioactivity for immobilized horseradish peroxidise on the NPP surface, resulting from its more similar physical and chemical properties to protein immobilized surfaces. For applications requiring a high degree of covalent immobilization of bioactive proteins and extended retention of bioactivity, the NPP surface is clearly preferred.
► Nitrogen-containing plasma polymer (NPP) has similar surface properties to proteins. ► NPP has higher protein covalent binding than diamond-like carbons (DLC). ► Immobilized enzymes on NPP have better retention than those on DLC.