A novel spatially constrained dual pincer DNA scaffold for bisphenol A detection

A novel spatially constrained dual pincer DNA scaffold was developed for Bisphenol A (BPA) detection. The dumbbell-shaped aptamer hairpin could be opened by target BPA. The two tails of opened aptamer-hairpin separately triggered the catalytic hairpin assembly between the two hairpins at both ends of DNA scaffold through the proximity effect. The effective concentration of the hairpins on dual pincer DNA scaffold greatly increased about 2800 fold due to the spatial constraint design. A good dynamic correlation was shown from 10 pM to 300 pM. The limit of detection was as low as 3 pM according to the 3σ/slope protocol. Real sample detection confirmed that dual pincer DNA scaffold could be effectively used for food and environmental monitoring with accurate sensing.