Self-Assembly of Proteinaceous Shells around Positively Charged Gold Nanomaterials Enhances Colloidal Stability in High-Ionic-Strength Buffers.

The enzyme lumazine synthase (LS) has been engineered to self-assemble into hollow-shell structures that encapsulate unnatural cargo proteins through complementary electrostatic interactions. Herein, we show that a negatively supercharged LS variant can also form organic-inorganic hybrids with gold nanomaterials. Simple mixing of LS pentamers with positively charged gold nanocrystals in aqueous buffer spontaneously affords protein-shelled gold cores.

Surface-Engineered Cationic Nanocrystals Stable in Biological Buffers and High Ionic Strength Solutions.

Progress in colloidal synthesis in the last two decades has enabled high-quality semiconductor, plasmonic, and magnetic nanocrystals (NCs). As synthesized, these NCs are usually capped with long-chain apolar ligands. Postsynthetic surface functionalization is required for rendering such NCs colloidally stable in polar media such as water.