title: Chemiluminescence assay for the sensitive detection of iodide based on extracting Hg2+ from a T-Hg(2+)-T complex.
abstract: A simple and sensitive chemiluminescence assay for iodide (I(-)) detection was reported, which was based on iodide extracting Hg(2+) from DNA featuring a stem-loop structure containing T-Hg(2+)-T. Specifically, Hg(2+) induced random coiled G-rich single-strand DNA to form a stem-loop structure containing T-Hg(2+)-T. Because the binding of Hg(2+) and I(-) is much stronger than that of Hg(2+) and thymine (T), I(-) could extract Hg(2+) from the stem-loop structure, releasing the DNA, which then bound with K(+) and transformed into a K(+)-stabilized G-quadruplex (with hemin as a cofactor), which catalyzed the H(2)O(2)-mediated oxidation of luminol. The produced chemiluminescence as a sensing signal was applied to sensitively and selectively detect iodide with a detection limit of 12 nM. This system exhibited the first DNAzyme-based iodide sensor. Finally, the sensor was successfully applied for iodide detection in real lake water samples.
authors: Department of Chemistry, Beijing Normal University, Beijing, 100875, PR China.
authors: Tao
authors: T
authors: Li
authors: Gang
authors: G
authors: Liang
authors: Xiaohong
authors: X
authors: Li
mesh_terms: D002413:Cations, Divalent / Q000032:analysis; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007454:Iodides / Q000032:analysis*; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000191:economics / Q000379:methods*; D008165:Luminol / Q000737:chemistry; D008628:Mercury / Q000302:isolation & purification; D010084:Oxidation-Reduction; D013941:Thymine / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D007454:Iodides; D008165:Luminol; D006427:Hemin; D004247:DNA; D006861:Hydrogen Peroxide; D008628:Mercury; D013941:Thymine