DNA-assembled Au nanodisk-nanorod architecture: An extended plasmonic Born−Kuhn model with tunable chiroptical activity

Controlled three-dimensional chiral arrangement of plasmonic nanocomponents is crucial for understanding emergent light-matter interactions but remains challenging, particularly for heterogeneous plasmonic nanoparticles with distinct shape anisotropy. Here, using an elaborately designed DNA assembly strategy, we constructed hybrid chiral plasmonic systems integrating gold nanodisks and nanorods. Chiroptical activity arises from the asymmetric lateral displacement between them, and the sign and intensity of the circular dichroism are determined by the number and handedness of the nanorod arrangements. We reveal that this chiroptical activity originates from selective plasmonic coupling between the in-plane resonance of the nanodisks and the longitudinal resonance of the nanorods, representing an experimental realization of an extended plasmonic Born−Kuhn model. This work opens new avenues in plasmonics and nanophotonics by providing a design paradigm for constructing complex chiral architectures.