DNA-Programmed Assembly of Nanoparticle Superlattices with Dynamic and Tailorable Mechanical and Optical Phenomena

The programmability of DNA makes it an attractive structure-directing ligand for the assembly of nanoparticle superlattices with unique structure-dependent physical phenomena. While DNA base pairing has enabled the development of materials with nanometer-scale precision in nanoparticle placement and independent control over particle size, lattice parameters, and crystal symmetry, manipulating the macroscopic shape of the lattices remains challenging. Additionally, the measurement of specific properties or fabrication of devices enabled by these structures remain underexplored areas compared to advancements in their synthesis. Here, we examine at-equilibrium deposition processes capable of generating single crystals with well-defined shapes that ultimately allow for the synthesis of complex mechanical and optical materials. We will demonstrate how the programmability of DNA can be used to synthesis nanoparticle superlattices of well-defined and faceted micron-scale crystallites, and how these crystallites can be used for fundamental studies on the hierarchical mechanical properties of DNA-assembled materials. We will also demonstrate one of the first examples of a DNA-nanoparticle superlattice device that allows for angular dependent reflectance for the purpose of coupling out-of-plane light sources. Finally, we will demonstrate how stabilization of these superlattices in gels allows for their structures to be dynamically altered as a function of different chemical and physical stimuli. Together, these experiments show that fundamental scientific understanding of nanoscale assembly with DNA results in a powerful tool for the synthesis of complex hierarchical structures with beneficial physical characteristics for device engineering.