title: A Quercetin Biosensor Based on Chitosan-Entrapped Carbon Nanotube Paste Electrode Coated with DNA.
abstract: This paper presents an easy, fast, low cost, and sensitive approach for the electrochemical determination of quercetin based on its intercalation into DNA double helix. Electrochemical studies of the interaction between quercetin and DNA showed a decrease in peak currents with a reduction in redox reversibility of quercetin in the presence of the DNA. The electrochemical behavior of quercetin at a chitosan-entrapped carbon nanotube paste electrode coated with DNA was studied. A considerable increase was observed in the oxidation signal of quercetin at the DNA-coated electrode compared with a DNA-free electrode, indicating the preconcentration of quercetin due to its interaction with the surface-confined DNA layer. After optimizing the main experimental parameters influencing the biosensor response, its performance was evaluated from an analytical point of view. Two linear dependences of the anodic peak current of quercetin on its concentration were observed in the ranges of 0.40-7.50 and 7.50-30.0 μmol/L, with LOD and LOQ of 0.039 and 0.13 μmol/L, respectively. The proposed biosensor was successfully applied to the analysis of black and green tea extracts for their quercetin content.
authors.affiliation: Shahid Bahonar University of Kerman, Department of Chemistry, Kerman, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Rezazadeh
authors.forename: Maryam
authors.initials: M
authors.lastname: Mohamadi
authors.forename: Daryoush
authors.initials: D
authors.lastname: Afzali
authors.forename: Tayebeh
authors.initials: T
authors.lastname: Shamspur
authors.forename: Ali
authors.initials: A
authors.lastname: Mostafavi
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009824:Ointments; D010084:Oxidation-Reduction; D011794:Quercetin / Q000032:analysis*; D013662:Tea / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D009824:Ointments; D013662:Tea; D002244:Carbon; D004247:DNA; D048271:Chitosan; D011794:Quercetin