title: Biosensor based on ds-DNA decorated chitosan modified multiwall carbon nanotubes for voltammetric biodetection of herbicide amitrole.
abstract: The interaction of amitrole and salmon sperm ds-DNA was studied using UV-vis and differential pulse voltammetry (DPV) at both bare and DNA-modified electrodes. Amitrole showed an oxidation peak at 0.445 V at a bare pencil graphite electrode (PGE). When ds-DNA was added into the amitrole solution, the peak current of amitrole decreased and the peak potential underwent a shift. UV-vis spectra showed that the absorption intensity of the ds-DNA at 260 nm decreased with increasing amitrole concentration, proving the interaction between amitrole and the ds-DNA. The results also showed that amitrole could interact with the ds-DNA molecules via the intercalative binding mode. Finally, a pretreated pencil graphite electrode (PGE) modified with multiwall carbon nanotubes (MWCNTs) and chitosan (CHIT) decorated with the ds-DNA were tested in order to determine amitrole content in solution. Electrochemical oxidation of amitrole bonded on DNA/MWCNTs-CHIT/PGE was used to obtain an analytical signal. A linear dependence was observed to exist between the peak current and 0.025-2.4 ng mL(-1) amitrole with a detection limit of 0.017 ng mL(-1). The sensor showed a good selectivity and precision for the determination of amitrole. Finally, applicability of the biosensor was evaluated by measuring the analyte in soil and water samples with good selectivity.
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran. Ensafi@cc.iut.ac.ir
authors.forename: Ali A
authors.initials: AA
authors.lastname: Ensafi
authors.forename: Maryam
authors.initials: M
authors.lastname: Amini
authors.forename: Behzad
authors.initials: B
authors.lastname: Rezaei
mesh_terms: D000640:Amitrole / Q000032:analysis*; D000818:Animals; D015374:Biosensing Techniques; D048271:Chitosan / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D006540:Herbicides / Q000032:analysis*; D008297:Male; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012474:Salmon; D013094:Spermatozoa / Q000737:chemistry
chemical_list: D006540:Herbicides; D037742:Nanotubes, Carbon; D006108:Graphite; D004247:DNA; D048271:Chitosan; D000640:Amitrole