Antifouling property of nanostructured surfaces prepared by self-assembly of block copolymer micelles (I): Protein adsorption

Biofouling and microbial adsorption are major contaminants of susceptible surfaces in biomedical, food, and membrane applications. Polymer brushes and zwitterionic polymers have been used to create effective protein-resistant antifouling surface coatings due to their strong hydration. In contrast, our recent work has shown that ultrathin polymer films of non-charged homopolymers on silicon (Si) substrates exhibit superior protein resistance. In this presentation, we use polymer micelle structures (hereafter “nanodomes”) to investigate the effect of surface geometry, such as domain spacing and height, on protein adsorption. Nanodomes were prepared by spin coating of polystyrene-b-poly(2-vinylpyridine) in p-xylene solutions, which form P2VP-core-PS-shell micelles, onto Si substrates. Fluorescein isothiocyanate-labeled bovine serum albumin and Alexa Fluor 488-labeled fibrinogen were used. Protein solutions were applied to the samples for 30 min at 25^oC, then gently rinsed with water and dried with air. Protein adsorption was quantified by photon-counting spectrofluorometry. We observed much less protein adsorption on the nanodome surfaces than on planar surfaces of similar film thickness, regardless of protein type, indicating that nanoscale surface topography plays a crucial role in protein adsorption.