title: Folding-upon-binding and signal-on electrochemical DNA sensor with high affinity and specificity.
abstract: Here we investigate a novel signal-on electrochemical DNA sensor based on the use of a clamp-like DNA probe that binds a complementary target sequence through two distinct and sequential events, which lead to the formation of a triplex DNA structure. We demonstrate that this target-binding mechanism can improve both the affinity and specificity of recognition as opposed to classic probes solely based on Watson-Crick recognition. By using electrochemical signaling to report the conformational change, we demonstrate a signal-on E-DNA sensor with up to 400% signal gain upon target binding. Moreover, we were able to detect with nanomolar affinity a perfectly matched target as short as 10 bases (K(D) = 0.39 nM). Finally, thanks to the molecular "double-check" provided by the concomitant Watson-Crick and Hoogsteen base pairings involved in target recognition, our sensor provides excellent discrimination efficiency toward a single-base mismatched target.
authors.affiliation: Dipartimento di Scienze e Tecnologie Chimiche, University of Rome, Tor Vergata , Via della Ricerca Scientifica 1, 00133 Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Idili
authors.forename: Alessia
authors.initials: A
authors.lastname: Amodio
authors.forename: Marco
authors.initials: M
authors.lastname: Vidonis
authors.forename: Jacob
authors.initials: J
authors.lastname: Feinberg-Somerson
authors.forename: Matteo
authors.initials: M
authors.lastname: Castronovo
authors.forename: Francesco
authors.initials: F
authors.lastname: Ricci
mesh_terms: D020137:Base Pair Mismatch; D004247:DNA / Q000032:analysis*; D015342:DNA Probes / Q000737:chemistry / Q000378:metabolism; D055664:Electrochemical Techniques; D004566:Electrodes; D008751:Methylene Blue / Q000737:chemistry; D018625:Microscopy, Atomic Force; D009693:Nucleic Acid Hybridization; D010084:Oxidation-Reduction
chemical_list: D015342:DNA Probes; D004247:DNA; D008751:Methylene Blue