Adjusting the Metrics of 1-D Helical Gold Nanoparticle Superstructures Using Multivalent Peptide Conjugates.
The properties of nanoparticle superstructures depend on many factors, including the structural metrics of the nanoparticle superstructure (particle diameter, interparticle distances, etc.). Here, we introduce a family of gold-binding peptide conjugate molecules that can direct nanoparticle assembly, and we describe how these molecules can be systematically modified to adjust the structural metrics of linear double-helical nanoparticle superstructures. Twelve new peptide conjugates are prepared via linking a gold-binding peptide, AYSSGAPPMPPF (PEP(Au)), to a hydrophobic aliphatic tail. The peptide conjugates have 1, 2, or 3 PEP(Au) headgroups and a C12, C14, C16, or C18 aliphatic tail. The soft assembly of these peptide conjugates was studied using transmission electron microscopy (TEM), atomic force microscopy (AFM), and infrared (IR) spectroscopy. Several peptide conjugates assemble into 1-D twisted fibers having measurable structural parameters such as fiber width, thickness, and pitch that can be systematically varied by adjusting the aliphatic tail length and number of peptide headgroups. The linear soft assemblies serve as structural scaffolds for arranging gold nanoparticles into double-helical superstructures, which are examined via TEM. The pitch and interparticle distances of the gold nanoparticle double helices correspond to the underlying metrics of the peptide conjugate soft assemblies, illustrating that designed peptide conjugate molecules can be used to not only direct the assembly of gold nanoparticles but also control the metrics of the assembled structure.
Department of Chemistry, University of Pittsburgh , 219 Parkman Ave., Pittsburgh, Pennsylvania 15260, United States.
Andrea D
AD
Merg
Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright-Patterson AFB, Ohio 45433, United States.
Joseph
J
Slocik
Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States.
Martin G
MG
Blaber
Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States.
George C
GC
Schatz
Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright-Patterson AFB, Ohio 45433, United States.
Rajesh
R
Naik
Department of Chemistry, University of Pittsburgh , 219 Parkman Ave., Pittsburgh, Pennsylvania 15260, United States.
Nathaniel L
NL
Rosi
D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D013499:Surface Properties
D010455:Peptides; D006046:Gold