Figure 1.

Synthesis of IO-Au core-shell NPs by the direct deposition method. (A) Synthesis of IO-Au core-shell NPs by iterative hydroxylamine seeding. Top: Schematic of the preparation procedure. Bottom: TEM images of IO-Au core-shell NPs with zero, one, three, and five times of deposition of Au atoms via reduction of Au³⁺ with hydroxylamine, respectively. Scale bar: XX nm. Reprinted with permission from ref 49. Copyright (2009) American Chemical Society. (B) Synthesis of IO-Au core-shell NPs by hydroxylamine reduction of Au precursor on the surface of polymer-coated IO NPs. Left: Schematic of the preparation procedure. Right: TEM image of Fe₃O₄ NPs and Fe₃O₄-Au core-shell NPs. Reprinted by permission from Macmillan Publishers Ltd: [Nature Communications] (ref 44), copyright (2010).