A New Modular Approach to Nanoassembly: Stable and Addressable DNA Nanoconstructs via Orthogonal Click Chemistries
Thermodynamic instability is a problem when assembling and purifying complex DNA nanostructures formed by hybridisation alone. To address this issue, we have used photochemical fixation and orthogonal copper-free, ring strain-promoted, click chemistry for the synthesis of dimeric, trimeric and oligomeric modular DNA scaffolds from cyclic, double-stranded, 80-mer DNA nanoconstructs. This particular combination of orthogonal click reactions was more effective for nanoassembly than others explored. The complex nanostructures are stable to heat and denaturation agents and can therefore be purified and characterised. They are addressable in a sequence-specific manner by triplex formation and they can be reversibly and selectively deconstructed. Nanostructures utilising this orthogonal, chemical fixation methodology can be used as building blocks for nano-machines and functional DNA nanoarchitectures.