Patent ID: 7235228

Claim:
A method for making core/shell nanoparticles having magnetic metal core and fluorescent semiconductor shell structure, comprising: (a) making a micelle composition by mixing an aqueous ferromagnetic metal salt solution and a surfactant in an organic solvent and wherein said metal salt is selected from the group consisting of salts of Fe, Co, Ni, alloys thereof, and mixtures thereof; (b) making a micelle composition by mixing an aqueous reducing agent solution and a surfactant in an organic solvent; (c) mixing the micelle compositions of(a) and (b) wherein the reduction of said metal salt to said magnetic metal core is effected; (d) isolating and functionalizing said magnetic metal core by treating with a sulfide to form metal sulfide seed crystals on the surface thereof; (e) reacting said functionalized magnetic metal core with a fluorescent semiconductor material to form a fluorescent semiconductor shell on said magnetic metal core.