2008 Eighth Annual Beckman Scholars Symposium
Saturday Poster Session - July 29, 2006

Au and magnetic Au-Ni nanoparticles were synthesized using fifth generation hydroxyl-terminated polyamidoamine dendrimers as templates. The dendrimer interior amine groups were used to bind Ni and Au metal salts, which were then reduced with NaBH4. UV-visible spectroscopy indicated that the Au and Au-Ni dendrimer stabilized nanoparticles could be completely extracted from the dendrimer into toluene using 1-decanthiol to form monolayer protected clusters (MPCs). These MPCs had narrow size distributions with average diameters of 3.1 ? 0.8 nm for Au NPs and 3.0 ? 0.7 nm for the Au-Ni NPs by TEM. Atomic absorption spectroscopy showed that the ratio of Au to Ni 2.1 ? 0.3, which was the same as the ratio set in the NP synthesis. XPS data indicated Ni was present in the form of NiO. The magnetic mass susceptibility of Au-Ni MPCs were determined to be 5 x 10-4 emu/g Ni with the Evan’s Method1 and 9 x 10-4 emu/g Ni with Superconducting Quantum Interference Device (SQUID) measurements. Additionally, SQUID magnetometer measurements at 5 K indicated that the Au-Ni NPs were superparamagnetic with a saturation magnetization of 33 emu/g Ni. Results from CO oxidation catalysis studies and biological tolerance studies will also be presented.