This Small Business Technology Transfer Phase I project is for the manufacture of multifunctional magnetic core-shell nanoparticles to demonstrate the feasibility of synthesizing core-shell nanoparticles consisting of magnetic nanoparticle cores and gold and/or silver shells. Such nanocomposite materials will be engineered to display controllable surface reactivity (and biocompatibility) from the gold or silver shells, and magnetic separation capability from the magnetic cores. The broad impact of the proposed approach is three-fold in the development of multifunctional nanomaterials. First, the nanoengineering of the metals enables a drastic increase of the surface area and other changes in properties for better bio-probing and antibacterial activity. Secondly, the nanoscale gold/silver shells lead to reduction of the production costs, toxicity and better antimicrobial characteristics. Thirdly, the introduction of magnetic cores enables the capabilities of effective and controlled separation, delivery and targeting of the bio-probes and antibacterial agents. Such products target not only the same commercialization market as magnetic beads in magnetic separation but also many new areas of biotechnologies. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)