title: G-quadruplexes as sensing probes.
abstract: Guanine-rich sequences of DNA are able to create tetrastranded structures known as G-quadruplexes; they are formed by the stacking of planar G-quartets composed of four guanines paired by Hoogsteen hydrogen bonding. G-quadruplexes act as ligands for metal ions and aptamers for various molecules. Interestingly, the G-quadruplexes form a complex with anionic porphyrin hemin and exhibit peroxidase-like activity. This review focuses on overview of sensing techniques based on G-quadruplex complexes with anionic porphyrins for detection of various analytes, including metal ions such as K+, Ca2+, Ag+, Hg2+, Cu2+, Pb2+, Sr2+, organic molecules, nucleic acids, and proteins. Principles of G-quadruplex-based detection methods involve DNA conformational change caused by the presence of analyte which leads to a decrease or an increase in peroxidase activity, fluorescence, or electrochemical signal of the used probe. The advantages of various detection techniques are also discussed.
authors.affiliation: Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, Brno CZ-613 00, Czech Republic. vojtech.adam@mendelu.cz.
authors.forename: Branislav
authors.initials: B
authors.lastname: Ruttkay-Nedecky
authors.forename: Jiri
authors.initials: J
authors.lastname: Kudr
authors.forename: Lukas
authors.initials: L
authors.lastname: Nejdl
authors.forename: Darina
authors.initials: D
authors.lastname: Maskova
authors.forename: Rene
authors.initials: R
authors.lastname: Kizek
authors.forename: Vojtech
authors.initials: V
authors.lastname: Adam
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry*; D021881:DNA, Catalytic / Q000737:chemistry; D054856:G-Quadruplexes; D017353:Gene Deletion; D006801:Humans; D007477:Ions / Q000032:analysis / Q000737:chemistry; D008670:Metals / Q000032:analysis / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry; D009696:Nucleic Acids / Q000032:analysis / Q000737:chemistry; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics
chemical_list: D021881:DNA, Catalytic; D007477:Ions; D008670:Metals; D009696:Nucleic Acids; D009930:Organic Chemicals; D011506:Proteins; D016159:Tumor Suppressor Protein p53; D004247:DNA