Gold nanotriangles decorated with superparamagnetic iron oxide nanoparticles: A compositional and microstructural study

The combination of iron oxide and gold in a single nanoparticle results in both magnetic and plasmonic properties that can stimulate novel applications in bio-sensing, medical imaging, or therapeutics. Microwave assisted heating allows the fabrication of multi-component, multi-functional nanostructures by promoting selective heating at desired sites. Recently, we reported a microwave-assisted polyol route yielding gold nanotriangles decorated with iron oxide nanoparticles. Here, we present an in-depth microstructural and compositional characterization of the system using scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS). A method to remove the iron oxide nanoparticles from the gold nanocrystals and some insights on crystal nucleation and growth mechanisms are also provided.This research was partially funded by the Spanish Ministry of Economy and Competitiveness in co-funding with European Social Funds through the MAT2012-35324 project, the Severo Ochoa Programme for Centers of Excellence in R&D (SEV-2015- 0496) and the Ramón y Cajal program (AL, RyC-2010-06082) and the Generalitat de Catalunya (2014SGR213). Authors also acknowledge support of the Chinese Scholarship Council (SMY, 201206150053) and the following projects: COST Action MP1202, and the U.S. Department of Energy grant DE-FG02- 09ER46554 (JAH, STP). Work at Oak Ridge National Laboratory was supported by the Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.Peer Reviewe