| Deoxyribonucleic acid (DNA), which is well known for its biological role in preserving genetic information, is now attracting increasing interest from scientists working in nanotechnology. Among the merits that make DNA an excellent nanoscale building material, the programmability and biocompatibility really distinguish it from other organic and polymeric materials in constructing self-assembled functional nanoarchitectures. This dissertation focuses on using DNA to construct water-soluble multiplexed biosensing platforms for future diagnostic applications, as well as biologically replicating DNA nanostructures to explore the compatibility between the artificial DNA structures and natural biological systems. The ultimate goal of the study is to develop DNA-based biosensors that can perform accurate detection in living cells.;Presented here are a series of studies towards this goal. First, self-assembled signaling aptamer nanoarrays were constructed for protein detection. Multiplexed biosensing was then achieved using combinatorial color-coding nanoarrays. Moreover, signal amplification was introduced to the system for improved detection sensitivity. Second, artificial DNA nanostructures (Holliday junction and paranemic crossover DNA) were replicated both in vitro and in vivo with considerably high efficiency and fidelity. One of the intriguing findings is that the immobile Holliday junction can maintain its structural integrity inside the cell, suggesting the possibility of using self-assembled DNA nanostructures to carry out tasks such as biosensing and drug delivery in vivo. Third, functional DNA nanotubules were aligned on a surface as a proof-of-concept demonstration of merging bottom-up and top-down methods. Finally, minor-image DNA was used to construct designer nanostructures with nuclease-resistance. |
