DPM & CHU – Biology and Pathology Institute
We describe an aptamer-based sensing approach that signals the presence of small-molecule targets when fluorescent DNA probes are challenged with the Ni2+ or Co2+ quencher metal ions. Functional oligonucleotides targeting L-tyrosinamide (L-Tym), adenosine (Ade) or cocaine (Coc) were end-labeled by the Texas-Red fluorophore. A fluorescence quenching occurred upon association of these transition metal ions with the free conjugates. The formation of the target-probe complex, by the way of variations in the overall binding of quencher metal ions along the DNA strands, led to a partial restoration (for the Ade and Coc systems) or a further attenuation (for the L-Tym system) of the fluorescence intensity. The absolute signal gain varied from 40 to 180% depending on the target-probe pair investigated. The approach was also used to detect the compound Ade in a spiked biological matrix in one minute or less.
Detection of Small Molecules by Fluorescence Intensity using Single Dye Labeled Aptamers and Quencher Transition Metal Ions. B. Billet, B. Chovelon, E. Fiore, P. Faure, C. Ravelet, E. Peyrin. Biosens. Bioelectron. 2022, 205, 114091