title: Parylene C surface functionalization and patterning with pH-responsive microgels.
abstract: Parylene C is a polymer well-known for its inertness and chemical resistance, thus ideal for covering and sealing 3D substrates and structures by conformal coating. In the present study, the Parylene C surface is modified by functionalization with pH-responsive poly(methacrylic acid) microgels either over the whole surface, or in a pattern through a poly(dimethylsiloxane) stamp. The surface functionalization consists of two phases: first, an oxygen plasma treatment is used to make the surface superhydrophilic, inducing the formation of polar functional groups and surface topography modifications; then, the plasma-treated samples are functionalized by drop casting a solution of pH-responsive microgels, or in a pattern via microcontact printing of the same solution. While both techniques, namely, drop casting and microcontact printing, are easy to use, fast, and cheap, the microcontact printing was found to provide a more homogeneous functionalization and to be applicable to any shape of substrate. The functionalization effectiveness was tested by the repeated uptake and release of a fluorescent labeled monoclonal CD4 antibody at different pH values, thus suggesting a new sensing approach.
authors.affiliation: Center for Biomolecular Nanotechnologies (CBN) @UNILE, Istituto Italiano di Tecnologia (IIT) Via Barsanti , 73010 Arnesano (LE), Lecce, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Calcagnile
authors.forename: Laura
authors.initials: L
authors.lastname: Blasi
authors.forename: Francesco
authors.initials: F
authors.lastname: Rizzi
authors.forename: Antonio
authors.initials: A
authors.lastname: Qualtieri
authors.forename: Athanassia
authors.initials: A
authors.lastname: Athanassiou
authors.forename: Evangelos
authors.initials: E
authors.lastname: Gogolides
authors.forename: Massimo
authors.initials: M
authors.lastname: De Vittorio
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D016650:Fluorescein-5-isothiocyanate; D005455:Fluorescent Antibody Technique; D005782:Gels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen; D058626:Plasma Gases; D011108:Polymers / Q000737:chemistry*; D011109:Polymethacrylic Acids; D013499:Surface Properties; D014992:Xylenes / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D005782:Gels; D058626:Plasma Gases; D011108:Polymers; D011109:Polymethacrylic Acids; D014992:Xylenes; C030613:polymethacrylic acid; C011055:parylene; D016650:Fluorescein-5-isothiocyanate; D010100:Oxygen
keywords: Parylene C; oxygen plasma; pH-responsive; patterning; poly(methacrylic acid) microgels; surface functionalization