Engineering bioinspired molecular systems has attracted interest for creating complex nanomachineries capable of self-assembling and functioning within living cells. Deoxyribonucleic acid (DNA) is a promising candidate, found in nature as a double-stranded biopolymer that forms a double helix of nucleotides. These nucleotides are composed of a nitrogenous base along with a pentose deoxyribose sugar and a phosphate to form the sugar-phosphate backbone. The common nitrogenous bases are adenine (A), guanine (G), cytosine (C), and thymine (T). Through Watson-Crick base pairing, hydrogen bonding occurs between G-C and A-T, and is aided by π- π stacking interactions to arrange the structure into a double helix. Owing to several unique properties, such as biocompatibility, predictability, specificity, and programmability, DNA as a fundamental building block is capable of precise manipulation at the nanoscale.The DNA origami technique enables us to synthesize molecular architectures of almost any arbitrary shape by exploiting the double helical nature of DNA. The nanostructures are designed with precise spatial control and features for a wide variety of functions and applications, spanning structural biology, directed hybrid material assembly, nanocircuitry, nanorobotics, drug delivery, and biosensing.This dissertation focuses on two distinct directions in DNA nanotechnology, demonstrating the versatility and diversity of applicable DNA nanostructures. The first direction is the development of hybrid materials using “static” DNA origami structures as templates, hosting chemically modified probe strands that reduce metal ions into solid metal nanoclusters. Different nanocluster patterns were designed, demonstrating the site-specificity of metal nanoparticles decorated on DNA origami surfaces. Hierarchical assembly of these origami structures was also achieved, both before and after metallization. The second direction explores “dynamic” DNA origami, which requires a driving force to induce the directional molecular motion. A nanoclock structure was created for functionalization as a programmable rotational nanodevice. The clock’s arm was first locked and then subsequently released by applying strand displacement reactions, and further modified with a DNA motor strand on the arm, and fuel strands on the circular base to impart directional movement.
Tiffany R. Olivera (Thu,) studied this question.