De novo design and assembly of functional nano-materials, especially those from chemical synthesis and CVD growth, is a key foundation in nanotechnology and promises diverse applications in photovoltaics, plasmonics, and electronics. As an example, nanoparticle-structured floating gate enables fast data reading plus high information density. However, it is still challenging to integrate the low-dimensional nano-materials into architectures with both sub-10 nm uniformity and large-area programmable device architectures.
Recently, in the field of structural DNA nanotechnology, researchers are using nucleic acids (particularly DNA) to self-assemble sophisticated synthetic structures at 2-nm resolution in a highly scalable manner—billions of identical structures assembling simultaneously. One particular successful strategy is known as single-stranded DNA bricks. By encoding spatial positioning information into the complementary sequence design, our lab has constructed more than 100 2D/3D structures from the modular DNA bricks with the help of computer-aided design software. We further use the modularity of DNA bricks to engineer DNA brick crystals, micron-sized two-dimensional patterns with prescribed thickness up to 80 nm and complex 3D surface features.
Using DNA brick crystals as templates, we demonstrate the scalable integration of hundred metal nanoparticles into ordered programmable 2D/3D architectures and chiral surface, ranging from several hundreds nanometers to microns. Geometrical information of the prescribed nanoparticle architectures is firstly encoded into the linear sequences of DNA bricks. Under epitaxial growth condition, a DNA brick crystal is folded with the expected periodicity over micron scale. Printing gold nanoparticles, ranging from 5 nm to 30 nm, onto the prescribed positions on the DNA brick crystal templates through surface DNA hybridization produces the prescribed plasmonic architectures with sub-5 nm positioning precision.
Besides metal nanoparticles, carbon nanotubes (CNT) can also be aligned onto DNA brick crystals to form micron scale 2D parallel arrays with prescribed pitch dimensions from around 8 nm to 24 nm at sub-5 nm positioning precision.
Developing DNA brick crystal-based scaling-up approach will bridge current synthetic foundation for functional nano-materials to the emerging nano-electronic applications. By rational control the structural parameters of DNA brick crystals, the architecture of the assembled nano-materials can be de novo designed and reliably fabricated in a scalable manner. High-resolution feature of DNA brick crystal further scales the positioning resolution of nano-materials to around 2 nm.