Three-dimensional metal dielectric structures are disclosed with chiral symmetry that elicit surface plasmons. The plasmons may have propagational circular polarization wherein the frequency of such propagating plasmons may be tuned by design to couple with the electronic transitions or fundamental vibrations, including phonons, of a molecular species. The plasmon-molecule coupling, combined with the propagational polarization afforded by the chiral structure may be further exploited to mediate the chemical transformations involving molecules with spatial chirality and/or to detect molecules with spatial chirality.