Highly simplified double crossover (DX) motifs in structural DNA nanotechnology and their applications
Abstract
Structural DNA nanotechnogy has found its application in nanomechanical devices, molecular computation and templated nanoelectronic components. In the past 20 years, many different strategies have been exploited for structural DNA building blocks and a wide variety of patterns have been constructed. In this thesis, we designed and synthesized a series highly simplified double crossover (sDX) DNA motifs, these sDX molecules can self-assemble into large two-dimensional or one-dimensional crystals, but require minimum number of different oligonucleotide strands. We first applied "sequence symmetry" as a tool for a double crossover design. Sequence symmetry not only greatly simplifies the DNA motif design, but also dramatically increases the size of fully assembled crystals. In chapter two, we demonstrated that large two-dimensional DNA crystals could be self-assembled from only two different DNA strands. In chapter three, a long, robust DNA-only nanotube has been self-assembled from a single strand DNA, which would be the DNA motif that requires the least different strand DNA. In chapter four, utilizing the DNA nanotube as a template, we successfully synthesized a palladium nanowire that faithfully replicates its template. The palladium nanowires are 30-70nm wide, 10-17 nm high, and about 30 micrometers long. A streptavidin wrapped nanotube was successfully constructed when a biotin modified DNA strand was doped into the DNA fiber. The DNA templated protein one-dimensional array was confirmed by AFM. Finally, in chapter five, we applied the nanotube-like structure as a MRI contrast agent. We found that DNA could be conjugated to DOTA-Gd complex, such conjugates could be further self-assembly into nanofibers, we tested the relaxivity of our system, compared to the control experiment (single strand DNA, relaxivity 6.9 mM-1s-1), the nanofibers has gained proton relaxivity by 140% (relaxivity 16.8 mM-1s -1).
Degree
Ph.D.
Advisors
Mao, Purdue University.
Subject Area
Biochemistry|Organic chemistry
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