Assembly of peptide coated gold nanoparticles

The assembly of nanoparticles (NPs) into the desired organizations and patterns is critically important for construction of higher structures using nanoparticles as building blocks. The future of nanotechnology mostly depends on the directing the NPs to desired locations and orientations in the construction of predetermined structures. Peptide modification of NPs has been increasingly used for this purpose. In this regard, we designed different sized and charged peptides that can stably bind to gold nanoparticles (AuNPs). Then, we have investigated how the peptide binding to the nanoparticle surface can influence the assembly of the AuNPs in suspension and on hydrophilic surfaces from a drying droplet of their colloidal suspension. We first studied the effect of anionic peptide modification on assembly of the AuNPs in suspension and on surfaces and then we studied the effect of cationic peptide modification. We found that the peptide charge along with the size has a dominating effect on the behavior of the AuNP in suspension and on surfaces. The knowledge acquired from this work may offer simple and new techniques in assembly of nanostructures.