title: A Silver DNAzyme.
abstract: Silver is a very common heavy metal, and its detection is of significant analytical importance. DNAzymes are DNA-based catalysts; they typically recruit divalent and trivalent metal ions for catalysis. Herein, we report a silver-specific RNA-cleaving DNAzyme named Ag10c obtained after six rounds of in vitro selection. Ag10c displays a catalytic rate of 0.41 min(-1) with 10 μM Ag(+) at pH 7.5 with 200 mM NaNO3, while its activity is completely inhibited with the same concentration of NaCl. Ag10c is highly specific for Ag(+) among all the tested metals. A catalytic beacon biosensor is designed by labeling a fluorophore and a quencher on the DNAzyme. Fluorescence enhancement is observed in the presence of Ag(+) with a detection limit of 24.9 nM Ag(+). The sensor shows a similar analytical performance in Lake Huron water. This is the first monovalent transition metal dependent RNA-cleaving DNAzyme. Apart from its biosensor application, this study strengthens the idea of exploring beyond the traditional understanding of multivalent ion dependent DNAzyme catalysis.
authors.affiliation: Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario Canada , N2L 3G1.
authors.forename: Runjhun
authors.initials: R
authors.lastname: Saran
authors.affiliation: Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario Canada , N2L 3G1.
authors.forename: Juewen
authors.initials: J
authors.lastname: Liu
mesh_terms: D055162:Biocatalysis / Q000187:drug effects; D015374:Biosensing Techniques; D021881:DNA, Catalytic / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D005453:Fluorescence; D012834:Silver / Q000032:analysis* / Q000378:metabolism* / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D021881:DNA, Catalytic; D012834:Silver; D012965:Sodium Chloride