A laboratory study found that a second DNA aptamer can recognize the shape a first aptamer adopts when it binds a small molecule. Researchers obtained suitable partners in three of four systems, with dopamine the exception. The peer-reviewed work opens a route to reading molecular binding through paired sensors, with test-strip experiments conducted in buffer rather than patient samples.
Aptamers are short nucleic-acid strands that bind selected targets. In laboratory work published on 5 November in Nature Chemistry, researchers paired them so that one detected the shape adopted by another after a small molecule attached. The second strand recognized an exposed docking surface. This supplied a way to report whether the first sensor had encountered its target, rather than relying solely on ordinary complementary DNA pairing.[1]
Suitable secondary strands emerged in three of the four systems tested, including those for serotonin and testosterone. The dopamine system yielded no equivalent partner under the conditions used. Other controls separated recognition of a target-bound shape from recognition of a free molecule or simply a DNA sequence. Shortening the primary strand could preserve target binding while eliminating its recognition by the secondary strand.[1]
The peer-reviewed study incorporated paired aptamers into plate-based measurements and gold-particle test strips. The strips were tried in buffer solutions, with variation between printed strips. Patient samples and clinical diagnostic performance remain outside the demonstrated scope. Proposed atomic contacts also include simulation-based interpretations, alongside the experimental evidence for shape-sensitive recognition.[1]
