title: Development of a new biosensor based on functionalized SBA-15 modified screen-printed graphite electrode as a nano-reactor for Gquadruplex recognition.
abstract: Gquadruplex is an active target for therapeutic purposes because of the evidence which suggest that G-rich region of the human genome may form Gquadruplex structure. The electrochemical biosensor was prepared by modifying screen-printed graphite electrode (SPE) with synthesized SBA-N-propylpipyrazine-N-(2-mercaptopropane-1-one) (SBA@NPPNSH) mesoporous structure to investigate the Gquadruplex DNA structure (G4DNA). Ascorbic acid (AA) is known as an antioxidant agent that induces reductive properties. It is also important for some therapeutic purposes. In this study, AA was used as the model ligand and its ability to interact with Gquadruplex structure was examined. The pore of SBA@NPPNSH structure can act as a nano-reactor and the interaction of G4DNA/AA is accomplished inside these channels. The structure of SBA@NPPNSH was characterized by transmission electron microscope (TEM), X-ray powder diffraction (XRD), thermo gravimetric analysis (TGA) methods and atomic force microscopy (AFM). The interaction of AA with G4DNA was studied in Tris-HCl buffer and also in the presence of [Fe(CN)6](3-) as a redox label using the CV method. CV current decreases with the increasing concentrations of AA due to the interaction of G4DNA/AA. Circular dichroism (CD) spectroscopy was used to examine the ability of AA to form Gquadruplexes from short and long complementary G4DNA strands. Studying the selectivity using different dsDNA sequences revealed that AA could stabilize G4DNA. Thus, the proposed biosensor can distinguish G4DNA structure from other dsDNA structures.
authors.affiliation: Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Bagheryan
authors.affiliation: Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran. Electronic address: j.raoof@umz.ac.ir.
authors.forename: Jahan-Bakhsh
authors.initials: JB
authors.lastname: Raoof
authors.affiliation: Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Ojani
authors.affiliation: Department of Organic Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
authors.forename: Parizad
authors.initials: P
authors.lastname: Rezaei
mesh_terms: D015374:Biosensing Techniques; D002942:Circular Dichroism; D004566:Electrodes; D054856:G-Quadruplexes; D006108:Graphite; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D033362:Powder Diffraction; D013818:Thermogravimetry
chemical_list: D006108:Graphite
keywords: Ascorbic acid; Electrochemical biosensor; Genomic studies; Gquadruplex DNA; Mesoporous structure