  Molecular chirality plays a crucial role in innumerable biological processes.
The chirality of a molecule can typically be identified by its characteristic
optical response, the circular dichroism (CD). CD signals have thus long been
used to identify the state of molecules or to follow dynamic protein
configurations. In recent years, the focus has moved towards plasmonic
nanostructures, as they show potential for applications ranging from pathogen
sensing to novel optical materials. The plasmonic coupling of the individual
elements of such chiral metallic structures is a crucial prerequisite to obtain
sizeable CD signals. We here identified and implemented various coupling
entities - chiral and achiral - to obtain chiral transfer over distances close
to 100 nm. The coupling is realized by an achiral nanosphere situated between a
pair of gold nanorods that are arranged far apart but in a chiral fashion. We
synthesized these structures with nanometer precision using DNA origami and
obtained sample homogeneity that allowed us to directly demonstrate efficient
chiral energy transfer between the distant nanorods. The transmitter particle
causes a strong enhancement in amplitude of the CD response, the emergence of
an additional chiral feature at the resonance frequency of the nanosphere, and
a redshift of the longitudinal plasmonic resonance frequency of the nanorods.
Numerical simulations closely match our experimental observations and give
insights in the intricate behavior of chiral optical fields and the transfer of
plasmons in complex architectures.
