DNA Origami-Mediated Substrate Nanopatterning of Inorganic Structures for Sensing Applications

Structural DNA nanotechnology provides a viable route for building from the bottom-up using DNA as construction material. The most common
DNA nanofabrication technique is called DNA origami, and it allows high-throughput synthesis of accurate and highly versatile structures
with nanometer-level precision. Here, it is shown how the spatial information of DNA origami can be transferred to metallic nanostructures by
combining the bottom-up DNA origami with the conventionally used top-down lithography approaches. This allows fabrication of billions of tiny
nanostructures in one step onto selected substrates. The method is demonstrated using bowtie DNA origami to create metallic bowtie-shaped
antenna structures on silicon nitride or sapphire substrates. The method relies on the selective growth of a silicon oxide layer on top of the
origami deposition substrate, thus resulting in a patterning mask for following lithographic steps. These nanostructure-equipped surfaces can
be further used as molecular sensors (e.g., surface-enhanced Raman spectroscopy (SERS)) and in various other optical applications at the
visible wavelength range owing to the small feature sizes (sub-10 nm). The technique can be extended to other materials through methodological
modifications; therefore, the resulting optically active surfaces may find use in development of metamaterials and metasurfaces