Iron oxide composite nanoparticles and sensing properties

This paper reports findings of an investigation of the synthesis of monolayer-capped iron oxide and core (iron oxide)-shell (gold) nanocomposite and their assembly towards thin films as sensing materials. Pre-synthesized and size-defined iron oxide nanoparticles were used as seeding materials for the reduction of gold precursors, which was shown to be effective for coating the iron oxide cores with gold shells (Fe oxide@Au). The unique aspect of our synthesis is the formation of Fe oxide@Au core-shell nanoparticles with controllable surface properties. By controlling the reaction temperatures and manipulating the capping agent properties and solution compositions, the size, shape, composition, and monodispersity can be tailored. The core-shell nanoparticles were shown to form molecularly-mediated thin film assemblies using molecular mediators. The sensing properties of the nanostructures on piezoelectric devices were examined for the detection of volatile organic compounds. The preliminary results have provided important insights into the design of core-shell nanocomposites as sensing materials.