Purified DNA origami was mixed with thrombin-binding aptamers (TBA15 and HD22) with a ratio of three aptamer molecules for one docking site. The mixture was annealed in 1 × TAE-Mg2+ buffer containing 100 mM NaCl from 45 °C to 25 °C at a rate of 5 min/°C for six cycles.

Purified and concentrated origami-aptamers assemblies were achieved by performing poly (ethylene glycol)-induced depletion30. Briefly, origami-aptamers samples were mixed with PEG 8000 (15%), NaCl (500 mM) and MgCl2 (10 mM), then the mixture was centrifuged at 25 °C for 40 min at 16,000 × g. Removing supernatant, the pellet was dried by a vacuum centrifuge concentrator (CV200, Beijing Jiaimu, China) and resuspended in 1× TAE-Mg2+ buffer. The purified nanoarray solution was collected and quantified by UV–VIS spectrophotometer. The nanoarray was then characterized using 1% agarose gel electrophoresis and AFM.