Abstract

Preparation and characterization of nanocomposites of gold nanoparticles (AuNPs) using 3(rd) and 4(th) generation of poly(amidoamine) dendrimers (PAMAM) and modified PAMAM were studied. By utilizing poly-(ethylene glycol) grafted PAMAM G3 (PEG-G3), 9.7 +/- 3.1 nm gold particles were obtained; compared to particles of 15.4 +/- 7.3 nm size stabilized by unmodified PAMAM G3 dendrimers. In order to decrease the size of the synthesized gold nanoparticles the quaternization of primary amines in the periphery of PAMAM G4 (QG4) dendrimer was suggested. Characterization of the structures by fluorescence spectroscopy, UV-Vis spectrometry and transmission electron microscopy (TEM) revealed that PEG-G3 was better than PAMAM G4 as a templating agent, and that the QG4 dendrimer produced gold nanoparticles with the smallest size and the lowest polydispersity. The average size of gold nanoparticles protected by PAMAM G4 and QG4 were 13.9 +/- 4.5 and 6.1 +/- 1.6 nm, respectively.