Taking nanotech to sub-nanometre molecular technology
The 'Addressable molecular node assembly - a generic platform of nano-scale functionalised surfaces based on a digitally addressable molecular grid' (AMNA) project worked towards developing a nanotechnology platform based on a 100-nm-size grid of addressable molecular building blocks ('nodes'). The EU-funded project took this novel bottom-up modular approach in an effort to achievement placement of functional groups at defined positions with sub-nanometre precision. Team members developed a novel branching phosphoramidite monomer and synthesised functionalised oligonucleotides, containing it as a node. Systematic studies of oligonucleotide hybridisation succeeded in providing a platform for how to construct supramolecular double-stranded nets of oligonucleotides. Using fluorescence markers and investigating their energy transfer rates revealed how energy transfer can be used to gauge two-dimensional node structure. AMNA project partners also proved groundbreaking DNA hexagon assembly with novel trigonal DNA oligonucleotides for attachment to a lipid bilayer. They then developed and presented novel analytical techniques for characterising such DNA constructs. These and other study findings have already been published. A fluorescence microscope study of lipid-anchored DNA oligomers in a lipid layer showed how spreading, mixing and release behaviour of lipid-modified oligonucleotides can be controlled. This is important for prospective controlled mixing/hybridisation of oligonucleotides at lipid interfaces. Another study showed that a complementary DNA can be hybridised to a membrane-anchored lipid-modified oligonucleotide. Another achievement was further development of certain chemical methods for producing new cross-linked hexagons. These have the potential to serve as nanoconstruct building blocks instead of adding single oligonucleotides each time a network is constructed. AMNA project outcomes pave the way to the future development of a range of forceful nanotechnology applications that could revolutionise the field, with the size of integrated units and other functionalities being scaled down dramatically.
