Enhancing the plasmonic circular dichroism by entrapping chiral molecules at the core-shell interface of rod-shaped Au@Ag nanocrystals.

We report the enhancement of plasmonic circular dichroism (PCD) in cysteine-modified Au nanorods via Ag coating. The entrapment of cysteine at the Au-Ag interface effectively amplifies the local electromagnetic field and leads to strong enhancement of the PCD response. Ag coating on spherical nanoparticles modified with cysteine does not generate obvious PCD signals.