Surface Plasmon Coupling of Compositionally Heterogeneous Core-Satellite Nanoassemblies.
Understanding plasmon coupling between compositionally heterogeneous nanoparticles in close proximity is intriguing and fundamentally important because of the energy mismatch between the localized surface plasmons of the associated nanoparticles and interactions beyond classical electrodynamics. In this Letter, we explore surface plasmon coupling between silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), assembled in the form of core-satellite structures. A recently developed assembly method allows us to prepare ultrapure core-satellite nanoassemblies in solution, where 50 nm AgNPs are surrounded by 13 nm AuNPs via alkanedithiol linkers. We observe changes in the plasmon coupling between the AgNP core and AuNP satellites as the core-to-satellite gap distance varies from 2.3 to 0.7 nm. Comparison with theoretical studies reveals that the traditional hybridized plasmon modes are abruptly replaced by charge-transfer plasmons at a ∼1 nm gap. Changes with the number of satellites are also discussed.
†Department of Chemistry, Institute of Nanosensor and Biotechnology, Dankook University, 152 Jukjeon-ro, Suji-gu, Yongin, Gyeonggi 448-701, Korea.
Jun Hee
JH
Yoon
‡Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
Yong
Y
Zhou
‡Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
Martin G
MG
Blaber
‡Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
George C
GC
Schatz
†Department of Chemistry, Institute of Nanosensor and Biotechnology, Dankook University, 152 Jukjeon-ro, Suji-gu, Yongin, Gyeonggi 448-701, Korea.
Sangwoon
S
Yoon
charge transfer plasmon; core−satellite nanoassembly; generalized multiparticle Mie theory; heterogeneous nanoassembly; hybridization of surface plasmon mode; surface plasmon coupling