Protein Cage Directed Assembly of Binary Nanoparticle Superlattices

Area of Science:

• Materials Science
• Nanotechnology
• Biotechnology

Background:

• Inorganic nanoparticles self-assemble into superlattices with unique optical and magnetic properties.
• Protein cages can guide nanoparticle assembly into ordered structures.
• Creating ordered multi-component structures with diverse protein cages is challenging.

Purpose of the Study:

• To demonstrate the co-crystallization of two distinct protein cages with opposing surface charges and unequal diameters.
• To achieve binary metal nanoparticle superlattices within these protein cages.
• To provide insights for fabricating novel plasmonic and magnetic nanoparticle metamaterials.

Main Methods:

• Co-crystallization of cowpea chlorotic mottle virus and ferritin protein cages.
• Precise tuning of electrostatic attraction between protein cages.
• Encapsulation of gold and iron oxide nanoparticles within protein cage cavities.

Main Results:

• Formation of binary protein cage crystals with dimensions up to several tens of micrometers.
• Achievement of binary metal nanoparticle superlattices with an AB2FCC configuration.
• Demonstration of altered dipolar coupling and optical properties due to the superlattice structure.

Conclusions:

• The study successfully co-crystallized two different protein cages to form ordered binary structures.
• Binary metal nanoparticle superlattices were fabricated within these protein cages, exhibiting unique configurations.
• This work offers a pathway for designing advanced plasmonic and magnetic metamaterials.