Controlled aggregation of functionalized gold nanoparticles with a novel conjugated oligomer.

A new route is developed to control the self-assembly of gold nanoparticles (AuNPs) functionalized with a novel pyridyl-ended porphyrin-oligo(p-phenylene vinylene) conjugated oligomer (P-OPV-Py) into branched-rods, chain-networks, uniform fractal-like Au clusters, and larger nanoparticles. The techniques of optical spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) are used to characterize the self-assembly in various solvent systems (pure toluene, CHCl(3)/toluene, THF/toluene and n-butanol/toluene). A combination of the ligand/AuNPs molar ratio and relative concentration serves as the driving force to control the size and shape of P-OPV-Py capped AuNPs.