title: Electrochemical monitoring of the interaction of UO2(2+) with immobilized DNA.
abstract: Interaction of uranyl ion (UO2(2+)) with immobilized double strand calf thymus DNA (ds-ct-DNA) on zirconium attached gold-mercaptopropionic acid self-assembled monolayer (Au-MPA-Zr(IV) SAM) is monitored by electrochemical techniques. The results show that after 15 min proximity of the immobilized DNA with UO2(2+), the peak currents of the square wave voltammograms are decreased (about 80%), and the equivalent circuit model of electrochemical impedance spectroscopy (EIS) data, requires two constant phase elements (CPE) instead of only one. By using the surface concentration of DNA (≈2.3×10(-13) mol/cm(2)) and the number of the anthraquinonedisulfonic acid (AQDS) adsorbed on DNA (1.34×10(-10) mol/cm(2)) the ration of AQDS per DNA base pairs is obtained ≈1/30 before proximity to UO2(2+). Based on EIS technique, we find that the double strand structure of immobilized DNA on the electrode surface has been changed (damaged) by UO2(2+). This modified electrode has potential of becoming a screening tool for the rapid assessment of the interaction and genotoxicity of existing and new chemicals.
authors.affiliation: Department of Chemistry, University of Isfahan, Isfahan 81746-73441, I.R., Iran.
authors.forename: Sima
authors.initials: S
authors.lastname: Pourbeyram
authors.forename: Reza Karimi
authors.initials: RK
authors.lastname: Shervedani
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D058266:Dielectric Spectroscopy; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D061925:Immobilized Nucleic Acids / Q000737:chemistry*; D013499:Surface Properties; D017974:Uranium Compounds / Q000737:chemistry*
chemical_list: D061925:Immobilized Nucleic Acids; D017974:Uranium Compounds; D004247:DNA; C427203:calf thymus DNA; C012597:uranium dioxide