Engineering the inter-island plasmonic coupling in homometallic Au–Au_n core–satellite structures

We show that through strong ligand mediated interfacial energy control between Au seeds and the deposited Au, the non-wetting growth of Au on Au seeds led to the formation homometallic core–satellite nanostructures. To modulate the intraparticle plasmonic coupling between the core and the satellites, the number and size of the Au satellites, and their inter-island distances were continuously tuned by varying the growth kinetics. As a result of the precise structural control, the plasmonic absorptions of the core–satellite nanostructures were tuned from visible to near-infrared (NIR) spectral range, and the extent of spectral modulation (500–1300 nm) is among the best of the literature methods. This synthetic advance enriches the toolbox for nanosynthesis and points to a new direction in the exploration of sophisticated functional designs.