title: Chemiluminescent and chemiluminescence resonance energy transfer (CRET) detection of DNA, metal ions, and aptamer-substrate complexes using hemin/G-quadruplexes and CdSe/ZnS quantum dots.
abstract: Nucleic acid subunits consisting of fragments of the horseradish peroxidase (HRP)-mimicking DNAzyme and aptamer domains against ATP or sequences recognizing Hg(2+) ions self-assemble, in the presence of ATP or Hg(2+), into the active hemin-G-quadruplex DNAzyme structure. The DNAzyme-generated chemiluminescence provides the optical readout for the sensing events. In addition, the DNAzyme-stimulated chemiluminescence resonance energy transfer (CRET) to CdSe/ZnS quantum dots (QDs) is implemented to develop aptamer or DNA sensing platforms. The self-assembly of the ATP-aptamer subunits/hemin-G-quadruplex DNAzyme, where one of the aptamer subunits is functionalized with CdSe/ZnS QDs, leads to the CRET signal. Also, the functionalization of QDs with a hairpin nucleic acid that includes the G-quadruplex sequence in a ''caged'' configuration is used to analyze DNA. The opening of the hairpin structure by the target DNA assembles the hemin-G-quadruplex DNAzyme that stimulates the CRET signal. By the application of three different sized QDs functionalized with different hairpins, the multiplexed analysis of three different DNA targets is demonstrated by the generation of three different CRET luminescence signals.
authors.affiliation: Institute of Chemistry, Center of Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Ronit
authors.initials: R
authors.lastname: Freeman
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Liu
authors.forename: Itamar
authors.initials: I
authors.lastname: Willner
mesh_terms: D052157:Aptamers, Nucleotide / Q000032:analysis*; D019187:Cadmium Compounds / Q000737:chemistry; D004247:DNA / Q000032:analysis*; D031541:Fluorescence Resonance Energy Transfer; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry*; D007477:Ions / Q000032:analysis; D049449:Luminescence; D008628:Mercury / Q000032:analysis*; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D019187:Cadmium Compounds; D007477:Ions; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D006427:Hemin; D004247:DNA; C058667:cadmium selenide; D008628:Mercury; C031238:zinc sulfide