DNA origami-enhanced binding of aptamers to Staphylococcus aureus cells

The combination of DNA origami nanostructures and aptamers provides a powerful technology for diagnostic assays. Here, we functionalized a DNA origami nanostructure with a Protein-A binding aptamer to target Staphylococcus aureus bacterial cells. Using an enzyme-linked oligonucleotide assay (ELONA), we semi-quantitatively analyzed and compared the interaction of the aptamer and aptamer-modified DNA origamis with Staphylococcus aureus bacterial isolates. The results showed that aptamer-functionalized DNA nanostructures bind with five times higher affinity (KD: 34 ± 5 nM) compared to the aptamer alone (KD: 160 ± 9 nM). Visualising the interaction of bacterial cells and nanostructures with electron cryotomography further confirmed the aptamer-mediated specific interaction of DNA nanostructures with bacterial cells.