Controlled delivery of DNA origami on patterned surfaces

A strategy that combines top-down fabrication and bottom-up self-assembly to achieve deterministic position control of DNA origami structures over millimeter length scales on a wafer has been reported. A chemical strategy to attract and immobilize the origami onto gold surfaces using a carboxylic acid terminated self-assembled monolayer (SAM) has also been formulated. AFM micrographs revealed no DNA adsorption on SiO₂ surfaces whereas origami structures were clearly visible on the gold surfaces. The substrate was stringently washed using 1× TAE buffer, to avoid any specific physiosorption of gold nanoparticles. AFM in both height and phase modes clearly confirmed the delivery of gold nanoparticles onto individual origami rectangles on gold patterns. The method exploits fundamental processes of magnesium chelation and base-pair hybridization, which is scalable, robust, and reproducible.