title: Urea potentiometric enzymatic biosensor based on charged biopolymers and electrodeposited polyaniline.
abstract: A potentiometric biosensor based on urease was developed for the quantitative determination of urea concentration in aqueous solutions for biomedical applications. The urease was either physisorbed onto an electrodeposited polyaniline film (PANI), or immobilized on a layer-by-layer film (LbL) assembled over the PANI film, that was obtained by the alternate deposition of charged polysaccharides (carboxymethylpullulan (CMP) and chitosan (CHI)). In the latter case, the urease (Urs) enzyme was either physically adsorbed or covalently grafted to the LbL film using carbodiimide coupling reaction. Potentiometric responses of the enzymatic biosensors were measured as a function of the urea concentration in aqueous solutions (from 10(-6) to 10(-1) mol L(-1) urea). Very high sensitivity and short response time were observed for the present biosensor. Moreover, a stability study showed a higher stability over time for the potentiometric response of the sensor with the enzyme-grafted LbL film, testifying for the protective nature of the polysaccharide coating and the interest of covalent grafting.
authors.affiliation: Institut UTINAM, UMR CNRS 6213, Equipe Matériaux et Surfaces Structurés, Université de Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France. boris.lakard@univ-fcomte.fr
authors.forename: Boris
authors.initials: B
authors.lastname: Lakard
authors.forename: Delphine
authors.initials: D
authors.lastname: Magnin
authors.forename: Olivier
authors.initials: O
authors.lastname: Deschaume
authors.forename: Guilhem
authors.initials: G
authors.lastname: Vanlancker
authors.forename: Karine
authors.initials: K
authors.lastname: Glinel
authors.forename: Sophie
authors.initials: S
authors.lastname: Demoustier-Champagne
authors.forename: Bernard
authors.initials: B
authors.lastname: Nysten
authors.forename: Alain M
authors.initials: AM
authors.lastname: Jonas
authors.forename: Patrick
authors.initials: P
authors.lastname: Bertrand
authors.forename: Sami
authors.initials: S
authors.lastname: Yunus
mesh_terms: D000814:Aniline Compounds; D001704:Biopolymers; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D048271:Chitosan; D055664:Electrochemical Techniques; D004795:Enzyme Stability; D004800:Enzymes, Immobilized; D005936:Glucans; D006801:Humans; D011199:Potentiometry; D012680:Sensitivity and Specificity; D014508:Urea / Q000032:analysis* / Q000652:urine; D014510:Urease
chemical_list: D000814:Aniline Compounds; D001704:Biopolymers; D004800:Enzymes, Immobilized; D005936:Glucans; C410955:carboxymethylpullulan; C416807:polyaniline; D014508:Urea; D048271:Chitosan; D014510:Urease