Fig. 2: DNA origami carrier-based biosensors.

a Schematic representation of the DNA nanostructure-based biosensing concept exploiting translocation through nanopipettes as the sensing mechanism. b Schematic representation of the design and representative AFM micrographs of the unoccupied and occupied DNA origami carriers. The frame DNA nanostructure is ~95 nm × 95 nm in dimension with a 35 nm × 35 nm inner cavity. The DNA origami comprises small nucleotide ‘anchors’ that protrude into the cavity which facilitate the incorporation of the DNA aptamer via hybridisation. The DNA carrier also includes a polarity marker. c Peak amplitude and dwell time histograms of DNA nanostructure carriers (9 nM) and carriers incubated with CRP at 9 nM concentration, both measured at a final carrier concentration of 500 pM. d Typical ion current signatures upon translocation of CRP molecules, CRP–DNA aptamer complexes, unoccupied carriers and CRP-bound occupied carriers. The scale bars represent 20 pA and 1 ms, respectively. Source data are in the Source Data file.