Versatile strategy for precisely tailored core@shell nanostructures with single shell layer accuracy: the case of metallic shell.

We report a general well-controlled synthetic strategy to achieve meticulous control of metallic shell growth at the single monolayer level with versatile core nanoparticles, thus facilitating investigation of their scope for numerous applications. The central component of this strategy is to introduce an intermediate phase in a phase transfer reaction to finely tune shell growth process. Two different typed core nanoparticles with distinct functionality and surface chemistry, including metallic and semiconductor nanoparticles, are chosen to demonstrate versatility of our approach. Enabled by such, we further highlight importance and tunability of plasmonic and optical couplings with layer-by-layer shell control. Thus, our strategy should be important for understanding and manipulating fundamental nanoscale chemical and physical property as well as assembling nanostructures with desirable structure and functionality.