DNA-Functionalized 100 nm Polymer Nanoparticles from Block Copolymer Micelles

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Chemistry

Background:

• DNA-mediated self-assembly is key for creating colloidal superstructures.
• DNA-functionalized colloids are vital for nanophotonic materials and devices.
• Existing methods require precise control over nanoparticle size and DNA functionalization.

Purpose of the Study:

• To develop a method for synthesizing DNA-functionalized polymer nanoparticles (DNA-polyNPs) between 55-150 nm.
• To achieve high DNA conjugation density on the nanoparticle surface.
• To demonstrate the self-assembly of these DNA-polyNPs into ordered superstructures.

Main Methods:

• Utilized block copolymer micelles (polystyrene-b-poly(ethylene oxide) with azide end groups) as templates.
• Swelled micelle cores with styrene monomer and polymerized to form nanoparticles with PEO brushes and azide end groups.
• Conjugated DNA strands via strain-promoted alkyne-azide cycloaddition, achieving high DNA density.

Main Results:

• Successfully synthesized DNA-polyNPs in the 55-150 nm range.
• Achieved high DNA conjugation density (over one strand per 12.6 nm² for 70 nm particles).
• Demonstrated the formation of CsCl-type colloidal superstructures through DNA binding between complementary DNA-polyNPs.

Conclusions:

• The developed method provides a versatile route to DNA-functionalized polymer nanoparticles.
• These nanoparticles are suitable building blocks for creating complex, ordered colloidal superstructures.
• The strategy is promising for fabricating advanced nanophotonic materials and devices.