DNA-Functionalized 100 nm Polymer Nanoparticles from Block Copolymer Micelles*

DNA-mediated self-assembly of colloidal particles is one of the most promising approaches for constructing colloidal superstructures. For nanophotonic materials and devices, DNA-functionalized colloids with diameters of around 100 nm are essential building blocks. Here, we demonstrate a strategy for synthesizing DNA-functionalized polymer nanoparticles (DNA-polyNPs) in the size range of 55~150 nm using block copolymer micelles as a template. Diblock copolymers of polystyrene-b-poly(ethylene oxide) with an azide end group are first formed into spherical micelles. Then, micelle cores are swollen with styrene monomer and polymerized, thus producing PS nanoparticles with PEO brushes and azide functional end groups. DNA strands are conjugated onto the ends of the PEO brushes on the surface of PS particles through a strain-promoted alkyne-azide cycloaddition reaction (SPAAC). The DNA-polyNP with complementary sequences show thermally-responsive association and dissociation behavior