A colorimetric nanosensor based on a selective target-responsive aptamer kissing complex

Herein, we report a novel approach for the design of a colorimetric aptasensor based on functionalized gold nanoparticle probes. This approach relies on the conjugation of nanoparticles by two functional DNA and RNA hairpins that engage specific kissing (loop–loop) interactions in response to the addition of a small analyte ligand, leading to particle aggregation and then red-to-purple colour change of the colloidal solution.