Since irradiation of pso-TFO-loaded origami with 365 nm light stabilized the interactions between pso-TFO-PEG/bio and HP-origami, we sought further insight into the mechanism of this stabilization. To this end, we designed a further DNA origami containing exactly one hairpin (1HP) (Fig and). In this origami, the hairpin is formed between a reporter staple labelled with Cy5 (staple 1, shown in red) and an adjacent staple (staple 0, shown in orange).