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Updated: Apr 20, 2026
Synthesis and Characterization of Amphiphilic Gold Nanoparticles
Published on: July 2, 2019
Shape separation of gold nanoparticles using a pH-responsive amphiphilic dendrimer according to their shape
Minjia Hao1, Cheng Liu2, Ling Peng3
1Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloids and Surfaces, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Abstract:
We present a novel method for shape-selective separation of nanoparticles in aqueous media utilizing an amphiphilic cationic dendrimer (C18N5) through regulation of the pH of the dispersion medium. This amphiphilic dendrimer (C18N5) bears a poly(amidoamine) dendron with four terminal amine groups and one hydrophobic long alkyl chain, and it can strongly adsorb to the surface of gold nanoparticles at low pH and promote their aggregation at high pH. During aggregation, isotropic NPs with smaller inter-particle contact area have much better solution stability than anisotropic NPs. Therefore, isotropic NPs remain stable in the supernatant, while anisotropic NPs are subject to aggregation and subsequent precipitation. As a result of this simple separation strategy, gold nanoplates with a purity level of 97% (in number density) can be rapidly and conveniently achieved.
