Bioactive Antifouling Surfaces by Visible‐Light‐Triggered Polymerization

Hierarchical bioactive surfaces are created by visible‐light‐induced surface‐initiated living radical polymerization employing tris[2‐phenylpyridinato‐C2,N]iridium(III) as a photocatalyst. The hierarchical antifouling diblock copolymer structures consist of N‐(2‐hydroxypropyl)‐methacrylamide (first block) and carboxybetaine methacrylate (second block). The living nature of the polymerization is shown by a linear increase in layer thickness (as measured by atomic force microscopy) and reinitiation of the polymerization to create a patterned second block of polymer. The chemical structure of the brushes is confirmed by X‐ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy measurements. The block copolymer brushes demonstrate excellent antifouling properties when exposed to single‐protein solutions or to bovine serum. The second carboxybetaine block of the hierarchical antifouling structures can effectively be biofunctionalized with an anti‐fibrinogen antibody. The coated surfaces show a high affinity and specificity to fibrinogen, while preventing nonspecific adsorption from other proteins in bovine serum. Diblock bioactive antifouling polymer brushes are created by visible light triggered polymerization and further functionalized with antibodies for selective capture. The antifouling character of the polymer brushes is tested by exposing them to single protein solutions and bovine serum. The good antifouling and bioactive properties of the coatings indicate the potential of their applications in biosensors.