Selective Self-assembly of Gold Nanocrystals Using Complementary Leucine Zipper Peptides

A heterodimeric leucine zipper (Lz)-based peptide hybrid was utilized as a molecular adhesive to bind two types of gold nanocrystals with different shapes. An acidic leucine zipper (LzE) and a basic leucine zipper (LzK) peptides with terminal cysteine are respectively adsorbed to the surface of spherical gold nanoparticles (LzE-Au NPs) and gold nanocubes (LzK-Au NCs). Transmission electron microscope (TEM) observation and visible (Vis) absorption spectroscopy revealed that LzE-Au NPs and LzK-Au NCs are selectively self-assembled in water. The dynamic self-assembly behavior is also confirmed by in-situ fluorescence resonance energy transfer between fluorescence dyes connected to LzE and LzK peptides and other control experiments.