title: Amperometric biosensor based on prussian blue and nafion modified screen-printed electrode for screening of potential xanthine oxidase inhibitors from medicinal plants.
abstract: A simple and sensitive amperometric biosensor was developed for the screening of potential xanthine oxidase inhibitors from medicinal plants. This biosensor was prepared by immobilization of xanthine oxidase on the surface of prussian blue modified screen-printed electrodes using nafion and glutaraldehyde. The developed biosensor showed a linear amperometric response at an applied potential of +0.05 V toward the detection of hypoxanthine from 5 μM to 45 μM with a detection limit of 0.4 μM (S/N=3) and its sensitivity was found to be 600 mA M(-1) cm(-2). In addition, the biosensor exhibited a good storage stability. The inhibition of xanthine oxidase by allopurinol was studied under the optimized conditions. The linear range of allopurinol concentration is obtained up to 2.5 μM with an estimated 50% of inhibitionI50=1.8 μM. The developed biosensor was successfully applied to the screening of xanthine oxidase inhibitors from 13 medicinal plants belonging to different families. Indeed, Moroccan people traditionally use these plants as infusion for the treatment of gout and its related symptoms. For this purpose, water extracts obtained from the infusion of these plants were used for the experiments. In this work, 13 extracts were assayed and several of them demonstrated xanthine oxidase inhibitory effect, with an inhibition greater than 50% compared to spectrophotometry measurements that only few extracts showed an inhibition greater than 50%.
authors.affiliation: Laboratoire Génie des Procédés et Environnement, Faculté de Sciences et Techniques, Hassan II University of Casablanca, B.P.146, Mohammedia, Morocco.
authors.forename: Loubna
authors.initials: L
authors.lastname: El Harrad
authors.affiliation: Laboratoire Génie des Procédés et Environnement, Faculté de Sciences et Techniques, Hassan II University of Casablanca, B.P.146, Mohammedia, Morocco. Electronic address: azizamine@yahoo.fr.
authors.forename: Aziz
authors.initials: A
authors.lastname: Amine
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation / Q000379:methods; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology*; D005295:Ferrocyanides; D005465:Fluorocarbon Polymers; D006801:Humans; D010946:Plants, Medicinal / Q000737:chemistry*; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D005295:Ferrocyanides; D005465:Fluorocarbon Polymers; C040402:perfluorosulfonic acid; D014969:Xanthine Oxidase; C000170:ferric ferrocyanide
keywords: Allopurinol; Amperometric biosensor; Medicinal plants; Prussian blue; Screen-printed electrode; Xanthine oxidase