title: Electrochemical determination of biophenol oleuropein using a simple label-free DNA biosensor.
abstract: Oleuropein (Ole), naturally occurring phenolic compound found in olive products, is well known for its benefits for human health. In the present work, a simple, sensitive and rapid determination of Ole was achieved using a label-free electrochemical DNA biosensor. The application was related to the molecular interaction between Ole and double-stranded DNA (dsDNA). So, the voltammetric behavior of Ole at the surface of a DNA-immobilized chitosan-modified carbon paste electrode was studied using differential pulse voltammetry (DPV) where the oxidation peak current of Ole was measured as an analytical signal. A considerable increase was observed in the oxidation signal of Ole at the DNA-coated electrode compared with the DNA-free electrode, indicating the pre-concentration of Ole due to the interaction with the surface-confined DNA layer. In order to use the proposed sensor for real samples, different parameters affecting Ole signal such as, immobilization time and potential, accumulation time and pH, and stripping pH were optimized. Under optimized experimental conditions, a linear concentration range of 0.30-12μmolL(-1) with a detection limit of 0.090μmolL(-1) was obtained for Ole determination. The proposed biosensor was successfully applied to the determination of Ole in olive leaf extract and human serum samples.
authors.affiliation: Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran; Young Research Society, Shahid Bahonar University of Kerman, Kerman, Iran. Electronic address: m.mohamadi794@gmail.com.
authors.forename: Maryam
authors.initials: M
authors.lastname: Mohamadi
authors.affiliation: Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Mostafavi
authors.affiliation: Department of Biotechnology, Institute of Science, High Technology and Environmental Science, Graduate University of Advance Technology, Kerman, Iran. Electronic address: mtmahani@gmail.com.
authors.forename: Masoud
authors.initials: M
authors.lastname: Torkzadeh-Mahani
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D048271:Chitosan / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D006801:Humans; D006863:Hydrogen-Ion Concentration; D061925:Immobilized Nucleic Acids / Q000737:chemistry*; D057888:Iridoid Glucosides; D039823:Iridoids / Q000032:analysis* / Q000097:blood; D057230:Limit of Detection; D000069463:Olive Oil / Q000032:analysis
chemical_list: D061925:Immobilized Nucleic Acids; D057888:Iridoid Glucosides; D039823:Iridoids; D000069463:Olive Oil; C002769:oleuropein; D048271:Chitosan
keywords: DNA biosensor; Oleuropein; Olive leaf; Voltammetry