Plasmonic Core-Satellites Nanostructures with High Chirality and Bioproperty.

In this Letter, gold nanorods (Au NRs) and gold nanoparticles (Au NPs) were assembled into core-satellites (Au NR-NPs) nanostructures using DNA as the linkers. Circular dichroism (CD) measurements of the nanoassemblies displayed two plasmonic CD (PCD) peaks in the vicinity of the surface plasmon resonance (SPR). Interestingly, the number of Au NPs in the assemblies had a significant influence on the shape and intensity of the CD line. The assemblies were enzymatically disassembled by deoxyribonuclease I (DNase I), and the CD responses were simultaneously reversed. With the proof-of-concept design, the PCD response was no change by addding enzyme inhibitor. These experiments suggested that the chirality depended upon the structure of core-satellites nanoassemblies, and the results clarify that the possible origin of the optical activity comes from chiral arrangement of building blocks and Coulomb dipole-dipole interactions. This research also illuminated that the assemblies can be used to develop a new sensor for the sensitive screening of the enzyme inhibitors.