Implementation of Specific Bioconjugation in Polystyrene-block-poly(tert-butyl acrylate)-Based Bio-Interfaces

• Published in: Macromolecular symposia. Vol. 298; no. 1; pp. 64 - 71
• Main Authors: Wasse1, Ekram, Ghassemi, Sina, Schönherr, Holger
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.12.2010; WILEY‐VCH Verlag
• Subjects: Adsorption; biomaterials; Confocal; diblock copolymers; Dyes; Fluorescence; Immobilization; Microscopy; polymer biointerfaces; Proteins; Surface chemistry; thin films
• ISSN: 1022-1360; 1521-3900; 1521-3900
• DOI: 10.1002/masy.201000036

Here we report on the expansion of a previously introduced biointerface platform based on thin spin‐coated films of polystyrene‐block‐poly(tert‐butyl acrylate) (PS‐b‐PtBA). Following the selective deprotection of the tert‐butyl‐ester groups in the PtBA skin layer by hydrolysis under acidic conditions, the activation with N‐hydroxysuccinimide and the subsequent derivatization with α,ω‐biotin‐amine end‐functionalized poly(ethylene glycol) (PEG), strepavidin was immobilized as anchor layer for specific immobilization of biotin‐tagged molecules. Based on contact angle, Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and confocal fluorescence microscopy data it was shown that the polymer films were efficiently modified. The complexation of a biotin‐tagged dye, as well as the non‐specific adsorption of proteins was determined by confocal fluorescence microscopy measurements. The surface coverage of the immobilized dye as a function of dye concentration in solution was found to be consistent with a high affinity‐type adsorption isotherm, while the protein resistant properties were found to be similar to non‐biotinylated PEG. The scope of micro‐ and nanostructured PS‐b‐PtBA biointerfaces is thereby considerably expanded to encompass the specific immobilization of biotin‐tagged biomolecules.