One-step synthesis of Fe-Au core-shell magnetic-plasmonic nanoparticles driven by interface energy minimization

Directing the assembly of atoms into core–shell particles generally requires elegant but sophisticated procedures. Here we show how the thermodynamic driving force to minimization of surface and interfaceenergy can beexploited to produce colloidal Fe–Au core– shell nanoparticles in one step and with a yield approaching 99.7% in mass. This is obtained by laser ablation with nanosecond pulses of thin bimetallic films immersed in acetone. The Fe–Au core–shell nanoparticles show magnetic and plasmonic properties, and a surface available to bioconjugation and analytical assays. This laser assisted synthetic method represents a step forward in the facile preparation of core–shell nanospheres with multiple appealing functionalities.