Engineering Photonic Nanodevice by Prescribed Particles Organization and DNA-Based Self-Assembly

Engineering novel optical properties via self-assembly is a promising approach for the fabrication of complex photonic devices with light harvesting, light manipulation, and optical communication capacities. The ability to organize nanoparticles with precise spacing at different scales can enable the structured nanomaterial with emergent optical properties. However, the realization of such materials remains a challenge. We use a DNA-based self-assembly platform to fabricate three-dimensional (3D) optical materials with ordered nanoparticles. DNA origami frames with DNA complementary bonds can capture selective nano-cargo in prescribed spatial positions with nano-scale precision. Programmable bonds enable DNA origami to serve as building blocks that can self-assemble into 3D lattices with repeating and highly organized nanoparticle motifs. By designing an organized structure that couples plasmonic and light-emitting nanoparticles, we investigated the light-emitting properties of the assembled 3D arrays. The optical properties were strengthened by the site-specific growing of the plasmonic particles within the lattice. To enhance stability, the assembled materials were silicated prior to advanced material characterization and optical measurements. To characterize the assembled materials and to achieve the desired optical response, we used electron microscopy and small-angle X-ray scattering (SAXS) to optimize the assembly process, particle sizes, and particle organization. We further investigated the optical properties by optical microscopy and spectroscopy.