GoldHelix · Development of chiral plasmonic materials with the tailored optical response of self-assembled chiral nanocomposite.

The scientific community has been highly interested in developing molecular and photonic devices in recent years due to their multiple promising applications with flexible and cost-effective organic materials. Generally, nanophotonic materials are nanocomposites (hybrid materials) having a structural organization with unique geometries of incorporated organic molecules and inorganic metal nanoparticles or metal complexes at nano-dimension. The top-down and bottom-up approaches are adapted to fabricate such materials. Taking inspiration from the inherent chiral aspect of nature, artificial chiral nanocomposites are designed by scientists to manipulate their optical properties. In the fabrication of chiral nanocomposites, the organization and use of chiral objects at nanoscale dimensions are of extreme interest because their resultant chiral structures will have excellent optical activity and chiroptical properties with promising applications such as chiro-optical sensors, circular polarizers and negative refractive index of materials. In our proposal, we aim to create chiral plasmonic (CP) materials (nanocomposites) by organizing on the surface and creating in-situ plasmonic metal nanoparticles (MNPs) on helical poly(phenylacetylene)s (PPAs) chiral template, respectively. The local surface plasmon resonance characteristics of achiral MNPs will be an advantage for chirality transfer from template to surface plasmons of achiral MNPs. The helical PPAs follow the dynamic helical sense under external stimuli influence, which is controllable. Thus, taking advantage of the tunability of the chiral template, the switchable CP materials will be created having chiroptical properties for an opposite handedness of (P)- and (M)-helix containing plasmonic nanoparticles, unlike most of the natural biomolecules supporting one-handedness of chirality. And the final hybrid PPAs-MNPs (CP materials) will be converted into thin films to study liquid crystalline properties.