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A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions
Published on: February 5, 2016
Magnetism of Dendrimer-Coated Gold Nanoparticles: A Size and Functionalization Study
José A Ulloa1, Giulia Lorusso2,3, Marco Evangelisti2
1Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Concepción, 160-C, Calle Edmundo Larenas 129, 4070371 Concepción, Chile.
Abstract:
Highly sensitive magnetometry reveals paramagnetism in dendrimer-coated gold nanoparticles. Different types of such nanoparticles, as a result of (i) functionalizing with two distinct Percec-type dendrons, linked to gold via dodecanethiol groups, and (ii) postsynthesis annealing in a solvent-free environment that further promotes their growth have been prepared. Ultimately, for each of the two functionalization configurations, we obtain highly monodisperse and stable nanoparticles of two different sizes, with spherical shape. These characteristics allow singling out the source of the measured paramagnetic signals as exclusively arising from the undercoordinated gold atoms on the surfaces of the nanoparticles. Bulk gold and the functional groups of the ligands contribute only diamagnetically.
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