la7013573_si_002.pdf (2.78 MB)
Air and Water Free Solid-Phase Synthesis of Thiol Stabilized Au Nanoparticles with Anchored, Recyclable Dendrimer Templates
journal contribution
posted on 2007-10-23, 00:00 authored by John D. Gilbertson, Ganesh Vijayaraghavan, Keith J. Stevenson, Bert D. ChandlerSolid-phase synthetic templates for Au nanoparticles were developed using Merrifield resins and polyamidoamine
(PAMAM) dendrimers. This synthetic scheme affords the opportunity to prepare metal nanoparticles in the absence
of air and water, and it does not necessitate phase transfer agents that can be difficult to remove in subsequent steps.
Amine-terminated generation 5 PAMAM (G5NH2) dendrimers were grafted to anhydride functionalized polystyrene
resin beads and alkylated with 1,2-epoxydodecane to produce G5C12anch. The anchored dendrimers bound both CoII
and AuIII salts from toluene solutions at ratios comparable to those of solution phase alkyl-terminated PAMAM
dendrimers. The encapsulated AuIII salts could be reduced with NaBH4 to produce anchored dendrimer encapsulated
nanoparticles (DENs). Treatment of the anchored DENs with decanethiol in toluene extracted the Au nanoparticles
from the dendrimers as monolayer protected clusters (MPCs). After a brief NaCN etch, the anchored dendrimers were
readily recycled and a subsequent synthesis of decanethiol Au MPCs was performed with comparable MPC yield and
particle size distribution.