| Abstract
| - The synthesis and characterization of 1−3-nm diameter, structurally well-defined, bimetallic AuAgdendrimer-encapsulated nanoparticles (DENs) are reported. Three different bimetallic structures wereexamined: AuAg alloys synthesized by cocomplexation and subsequent reduction of dendrimer-encapsulated Au3+ and Ag+ and core/shell [Au](Ag) and [AuAg alloy](Ag) structures (for structured materials,brackets indicate the core metal and parentheses indicate the shell metal) synthesized by a sequentialloading method. Depending on the shell metal and its oxidation state, the AuAg nanoparticles can beextracted from the dendrimer into an organic phase using different surfactants. This provides a means foranalyzing the composition of the shell. UV−vis, TEM, and single-particle X-ray energy dispersivespectroscopy (EDS) were used to characterize the bimetallic DENs before and after extraction and showthat the extraction step does not alter the size or composition of the bimetallic nanoparticles.
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