Functionalization of cycloolefinpolymer surfaces by plasma-enhanced chemical vapour deposition: comprehensive characterization and analysis of the contact surface and the bulk of aminosiloxane coatings

摘要

The surface science of bioassay devices is of great importance in the development of modern diagnosticnplatforms. The quality of surface is one of the most important elements of the device, often governingnthe background response, hence controlling the sensitivity of an assay. Detailed surfacencharacterization and analysis are imperative for the preparation of reproducible coatings with desirednproperties. We performed a comprehensive characterization of 3-aminopropyl-triethoxysilane filmsnprepared under two different deposition conditions on COP slides. Two sets of slides were prepared, bynexposing them to plasma reaction for 30 seconds (A30 slide) and 4 minutes (A4 slide). While thenvariations in the deposition conditions seemed very subtle, the use of several powerful analytical toolsnhelped us to reveal some fundamental differences between the studied films in terms of bindingncapacity, swelling and adhesion. Overall, the A30 films, with a thickness of 5.12 nm, showed up to 40%nhigher binding capacity and 25% better adhesion than the thicker A4 coatings (28.15 nm). Uponncontact with aqueous media, a significant change was observed in terms of surface roughness.nThe A30 slides outperformed A4 slides, resulting in smoother surface, which is an important parameternfor biomolecule immobilisation. The use of the techniques described in this article is aimed to set newnstandards for the characterization and analysis of the substrate surface of the future diagnostic devices.