Soft Matter Macro and Micro-Photonics workshop

DNA origami for 3D photonic structures

Gregor Posnjak

Faculty of Physics and CeNS, Ludwig-Maximilian-University Munich, München, 80539 Bayern, German

Manufacturing of nanostructures on the scale of tens and hundreds of nanometers is a challenging task with far reaching consequences on material properties, e.g. optical properties or catalytic activity. DNA origami allows us to design arbitrary structures on the scale of tens of nanometers, which can be addressably modified with different chemical groups, molecules or particles with nanometer precision [1,2]. We have developed a protocol to assemble diamond structure crystals with a 160 nm periodicity [3]. These crystals can be coated in SiO2 to mechanically stabilise them for drying, dried without the SiO2 through critical point drying and coated with thin, conformal layers of various metal or metal oxide materials through atomic layer deposition [4]. We have shown that the diamond structure crystals behave as photonic crystals for UV light after coating with TiO2 [3] and as catalytic materials with a large active area after coating with IrO2 [4].

The versatility of the DNA origami approach to colloidal crystallization allows us to develop various types of crystals such as hexagonal diamond, stacked diamond crystals and clathrate crystals and at the same time to increase the periodicity of the crystals by assembling the DNA origami monomers with multiple scaffold sequences. This approach allows us to assemble crystals with periodicities on the scale of several hunderd nanometers, leading to optical reflections in the visible wavelength range. Because of the large pores in the crystals and the possibility of addresable modifications, the crystals can serve as matrices for functional materials.

[1] P. Rothemund, Folding DNA to create nanoscale shapes and patterns, Nature 440 (7082), 297-302
[2] S. Douglas et al., Self-assembly of DNA into nanoscale three-dimensional shapes, Nature 459 (7245), 414-418
[3] G Posnjak et al. Diamond-lattice photonic crystals assembled from DNA origami, Science 384: 781-785 (2024).
[4] A Ermatov et al. Fabrication of functional 3D nanoarchitectures via atomic layer deposition on DNA origami crystals, JACS 147 (11), 9519-9527