High-strength magnetically switchable plasmonic nanorods assembled from a binary nanocrystal mixture

Nature Nanotechnology 12, 228 (2017). doi:10.1038/nnano.2016.235 Authors: Mingliang Zhang, Daniel J. Magagnosc, Iñigo Liberal, Yao Yu, Hongseok Yun, Haoran Yang, Yaoting Wu, Jiacen Guo, Wenxiang Chen, Young Jae Shin, Aaron Stein, James M. Kikkawa, Nader Engheta, Daniel S. Gianola, Christopher B. Murray & Cherie R. Kagan Next-generation ‘smart’ nanoparticle systems should be precisely engineered in size, shape and composition to introduce multiple functionalities, unattainable from a single material. Bottom-up chemical methods are prized for the synthesis of crystalline nanoparticles, that is, nanocrystals, with size- and shape-dependent physical properties, but they are less successful in achieving multifunctionality. Top-down lithographic methods can produce multifunctional nanoparticles with precise size and shape control, yet this becomes increasingly difficult at sizes of ∼10 nm. Here, we report the fabrication of multifunctional, smart nanoparticle systems by combining top-down fabrication and bottom-up self-assembly methods. Particularly, we template nanorods from a mixture of superparamagnetic Zn0.2Fe2.8O4 and plasmonic Au nanocrystals. The superparamagnetism of Zn0.2Fe2.8O4 prevents these nanorods from spontaneous magnetic-dipole-induced aggregation, while their magnetic anisotropy makes them responsive to an external field. Ligand exchange drives Au nanocrystal fusion and forms a porous network, imparting the nanorods with high mechanical strengt...
Source: Nature Nanotechnology - Category: Nanotechnology Authors: Tags: Letter Source Type: research