DNA origami structures as calibration standards for nanometrology

In this work we have studied the feasibility of DNA origami nanostructures as dimensional calibration standards for atomic force microscopes (AFMs) at the nanometre scale. The stability of the structures and repeatability of the measurement have been studied, and the applicability for calibration is discussed. A cross-like Seeman tile (ST) was selected for the studies and it was found suitable for repeatable calibration of AFMs. The height of the first height step of the ST was 2.0 nm. Expanded standard uncertainty (k = 2) of the measurement U _c was 0.2 nm. The width of the ST was 88 nm and width of its arm was 28 nm with U _c = 3 nm. In addition, prepared dry samples were found out to be stable at least for 12 months.