  Chirality is a fundamental feature in all domains of nature, ranging from
particle physics over electromagnetism to chemistry and biology. Chiral objects
lack a mirror plane and inversion symmetry and therefore cannot be spatially
aligned with their mirrored counterpart, their enantiomer. Both natural
molecules and artificial chiral nanostructures can be characterized by their
light-matter interaction, which is reflected in circular dichroism (CD). Using
DNA origami, we assemble model meta-molecules from multiple plasmonic
nanoparticles, representing meta-atoms accurately positioned in space. This
allows us to reconstruct piece by piece the impact of varying macromolecular
geometries on their surrounding optical near fields. Next to the emergence of
CD signatures in the instance that we architect a third dimension, we design
and implement sign flipping signals through addition or removal of single
particles in the artificial molecules. Our data and theoretical modelling
reveal the hitherto unrecognized phenomenon of chiral plasmonic-dielectric
coupling, explaining the intricate electromagnetic interactions within hybrid
DNA-based plasmonic nanostructures.
