title: Amplified detection of DNA through the enzyme-free autonomous assembly of hemin/G-quadruplex DNAzyme nanowires.
abstract: An enzyme-free amplified detection platform is described using the horseradish peroxidase (HRP)-mimicking DNAzyme as an amplifying label. Two hairpin structures that include three-fourths and one-fourth of the HRP-mimicking DNAzyme in caged, inactive configurations are used as functional elements for the amplified detection of the target DNA. In the presence of the analyte DNA, one of the hairpins is opened, and this triggers the autonomous cross-opening of the two hairpins using the strand displacement principle. This leads to the formation of nanowires consisting of the HRP-mimicking DNAzyme. The resulting DNA nanowires act as catalytic labels for the colorimetric or chemiluminescent readout of the sensing processes (the term "enzyme-free" refers to a protein-free catalyst). The analytical platform allows the sensing of the analyte DNA with a detection limit corresponding to 1 × 10(-13) M. The optimized system acts as a versatile sensing platform, and by coaddition of a "helper" hairpin structure any DNA sequence may be analyzed by the system. This is exemplified with the detection of the BRCA1 oncogene with a detection limit of 1 × 10(-13) M.
authors.affiliation: Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Simcha
authors.initials: S
authors.lastname: Shimron
authors.forename: Fuan
authors.initials: F
authors.lastname: Wang
authors.forename: Ron
authors.initials: R
authors.lastname: Orbach
authors.forename: Itamar
authors.initials: I
authors.lastname: Willner
mesh_terms: D019313:BRCA1 Protein / Q000737:chemistry / Q000378:metabolism; D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D021881:DNA, Catalytic / Q000737:chemistry* / Q000378:metabolism; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry* / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D057230:Limit of Detection; D049449:Luminescence; D053770:Nanowires
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; D021881:DNA, Catalytic; D006427:Hemin; D004247:DNA; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase