Springer Verlag, Nano Research, 12(8), p. 4007-4023
DOI: 10.1007/s12274-015-0903-y
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A frontier topic in nanotechnology is the realization of multifunctional nanoparticles (NPs) by the appropriate combination of different elements of the periodic table. The coexistence of iron and silver in the same nanostructure, for instance, is interesting for nanophotonics, nanomedicine and catalysis. However, alloying of Fe and Ag is inhibited for thermodynamic reasons. Here it is described the synthesis of Fe-doped Ag NPs bypassing thermodynamics constraints by laser ablation in liquid solution. These NPs have an innovative structure consisting in a scaffold of face centered cubic metal silver alternating with disordered Ag - Fe alloy domains, all arranged in a truffle-like morphology. Fe-Ag NPs show the plasmonic properties of silver and the magnetic response of iron-containing phases, and the surface of Fe-Ag NPs can be functionalized in one step with thiolated molecules. Taking advantage of the multiple properties of Fe-Ag NPs, magnetophoretic amplification of plasmonic properties is demonstrated with proof-of-concept experiments of surface enhanced Raman scattering (SERS) and photothermal heating. The synthetic approach is of general applicability and virtually permits the preparation in one step of a large variety of multi-element NPs.