Nanoparticle Adsorption on Antifouling Polymer Brushes

Abstract

Polymer brushes have\nbeen widely used to functionalize surfaces\nand provide antifouling capabilities against proteins and cells. Many\nefforts have focused on methods for functionalization of antifouling\npolymer brush surfaces for interactions with specific cells, proteins,\nand bacteria, but none have focused on immobilizing nanoparticles\n(NPs) on these surfaces. This article demonstrates that both pristine\nNPs and protein-coated NPs can adsorb onto well-functioning antifouling\npolymer brush coatings formed from poly-l-lysine-<i>graft</i>-poly­(ethylene glycol) (PLL-<i>g</i>-PEG)\nand methoxy PEG–thiol. The role of ionic strength in solution,\nsubstrate surface material, and NP surface charge in the interaction\nwas investigated to explore the forces behind the interaction. The\nadsorption of different types of NPs onto the surface was studied,\ndetermining that polystyrene, gold, carbon black, and silica particles\ncan adsorb onto PLL-<i>g</i>-PEG. We show that the approach\ncan be applied in, and studied by, both surface plasmon resonance\nand fluorescence imaging and suggest its application as a means to\nstudy NP–protein interactions, such as the protein corona.\nNPs self-assembled at antifouling polymer brush surfaces provide a\nnovel platform for both scientific studies and applications in biotechnology.