Sprecher
Beschreibung
In recent years, DNA ability to self-assemble into predetermined geometries, following Watson−Crick base-pairing rules, allowed the tailoring of functional supramolecular systems, which opened several opportunities in the fields of nanotechnology and material science. In this context, the DNA origami technique represents a general way to construct nano-objects with defined static 3D shapes, while machine-like dynamic assemblies, whose structure can be programmed to switch across states, showed the potential to exert precise motion control over matter at the nano-size level. In a recent study, large tubular assemblies of hybrid DNA-based plasmonic nanomaterials, with programmable chiral properties, were attained [1]. Specifically, micrometer-long DNA templates were used to organize gold nanoparticles, providing an example of large chiroplasmonic nanostructures synthesized by a simple self-assembly process. Such DNA nanotube structures, detected with atomic force microscopy and electron microscopy, were nicely twisted in a “fusilli” fashion (i.e., a type of Italian pasta). These large structures could find application in the development of metamaterials for protein structure characterization and to manipulate circular dichroism responses.
DNA is also an exceptional building block for the fabrication of dynamic supramolecular systems with switchable geometries. In another recent study [2], a self-assembled and tunable plasmonic–fluorescent nanostructure was built using DNA as the scaffold. By controlling strand displacement reactions, we were able to obtain a precise sliding motion mechanism of two single-strand DNA rails which were connected by a DNA quasi-ring. This system resulted in a nano-mechanical structure, where six discrete configurations could be obtained. Depending on the configuration, specific distances were set between a DNA-tethered gold nanoparticle and a fluorophore, Sulfo-Cyanine3 (Cy3), which could be detected by fluorescence emission plasmonic enhancement/inhibition changes. Since the mechanism worked as a multi-state fluorescent reporter of sequence-specific nucleic acid strands, it could therefore find application as a biosensing platform and for in vivo imaging.
