DNA-Origami-Templated Silica Growth by Sol-Gel Chemistry

Improving the stability of DNA origami structures with respect to thermal, chemical, and mechanical demands will be essential to fully explore the real-life applicability of DNA nanotechnology. Here we present a strategy to increase the mechanical resilience of individual DNA origami objects and 3D DNA origami crystals in solution as well as in the dry state. By encapsulating DNA origami in a protective silica shell using sol-gel chemistry, all the objects maintain their structural integrity. This allowed for a detailed structural analysis of the crystals in a dry state, thereby revealing their true 3D shape without lattice deformation and drying-induced collapse. Analysis by energy-dispersive X-ray spectroscopy showed a uniform silica coating whose thickness could be controlled through the precursor concentrations and reaction time. This strategy thus facilitates shape-controlled bottom-up synthesis of designable biomimetic silica structures through transcription from DNA origami.