title: Autonomous replication of nucleic acids by polymerization/nicking enzyme/DNAzyme cascades for the amplified detection of DNA and the aptamer-cocaine complex.
abstract: The progressive development of amplified DNA sensors and aptasensors using replication/nicking enzymes/DNAzyme machineries is described. The sensing platforms are based on the tailoring of a DNA template on which the recognition of the target DNA or the formation of the aptamer-substrate complex trigger on the autonomous isothermal replication/nicking processes and the displacement of a Mg(2+)-dependent DNAzyme that catalyzes the generation of a fluorophore-labeled nucleic acid acting as readout signal for the analyses. Three different DNA sensing configurations are described, where in the ultimate configuration the target sequence is incorporated into a nucleic acid blocker structure associated with the sensing template. The target-triggered isothermal autonomous replication/nicking process on the modified template results in the formation of the Mg(2+)-dependent DNAzyme tethered to a free strand consisting of the target sequence. This activates additional template units for the nucleic acid self-replication process, resulting in the ultrasensitive detection of the target DNA (detection limit 1 aM). Similarly, amplified aptamer-based sensing platforms for cocaine are developed along these concepts. The modification of the cocaine-detection template by the addition of a nucleic acid sequence that enables the autonomous secondary coupled activation of a polymerization/nicking machinery and DNAzyme generation path leads to an improved analysis of cocaine (detection limit 10 nM).
authors.affiliation: Institute of Chemistry, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Fuan
authors.initials: F
authors.lastname: Wang
authors.forename: Lina
authors.initials: L
authors.lastname: Freage
authors.forename: Ron
authors.initials: R
authors.lastname: Orbach
authors.forename: Itamar
authors.initials: I
authors.lastname: Willner
mesh_terms: D052157:Aptamers, Nucleotide / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D003042:Cocaine / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D004261:DNA Replication / Q000235:genetics; D021881:DNA, Catalytic / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques; D009696:Nucleic Acids / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D058105:Polymerization
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D009696:Nucleic Acids; D003042:Cocaine