Coiled-Coil Peptide-Based Assembly of Gold Nanoparticles

Abstract

The ability to direct the assembly of inorganic nanoparticles using biomolecular recognition is of growing interest in the development of new materials and nanotechnology devices.[1,2] Previous studies have described the use of the highly specific biomolecular recognition systems of DNA,[3,4] the streptavidin/biotin system,[5,6] antibody/antigen systems,[7] and a peptide based linker system[8] to direct nanoparticle assembly. The reversibility of the biological assembly process has not been probed in depth for these nanoparticle systems, with the exception of temperature changes to control the assembly of DNA-linked nanoparticles.[3] For certain applications in medical science such as the generation of novel tunable and/or switchable materials potentially useful for sensing in vivo and drug delivery, the ability to dynamically assemble and disassemble such structures when triggered by physiologically accessible environmental conditions such as changes in pH would be valuable.[1,9] Here we report the coiled-coil-based assembly of gold nanoparticles and demonstrate that the system can be controlled under mild conditions (near-neutral pH and ambient temperature). The flexibility in design afforded by varying the peptide sequence to produce coiled coils with different stabilities is also highlighted through the generation of more stable binary nanoparticle systems with controlled spacing and architecture.