title: An electrochemical immunosensor based on covalent immobilization of okadaic acid onto screen printed carbon electrode via diazotization-coupling reaction.
abstract: In this work, an electrochemical method based on the diazonium-coupling reaction mechanism for the immobilization of okadaic acid (OA) on screen printed carbon electrode was developed. At first, 4-carboxyphenyl film was grafted by electrochemical reduction of 4-carboxyphenyl diazonium salt, followed by terminal carboxylic group activation by N-hydroxysuccinimide (NHS), N-(3-dimethylaminopropyle)-N'-ethyle-carbodiimide hydrochloride (EDC). Hexamethyldiamine was then covalently bound by one of its terminal amine group to the activated carboxylic group. The carboxyl group of okadaic acid was activated by EDC/NHS and then conjugated to the second terminal amine group on other side of the hexamethyldiamine through amide bond formation. After immobilization of OA, an indirect competitive immunoassay format was employed to detect OA. The immunosensor obtained using this novel approach allowed detection limit of 1.44 ng/L of OA, and was also validated with certified reference mussel samples.
authors.affiliation: IMAGES, EA 4218, Batiment S, Université de Perpignan, 52 avenue Paul Alduy, 66 860, Perpignan Cedex, France.
authors.forename: Akhtar
authors.initials: A
authors.lastname: Hayat
authors.forename: Lise
authors.initials: L
authors.lastname: Barthelmebs
authors.forename: Audrey
authors.initials: A
authors.lastname: Sassolas
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Marty
mesh_terms: D000327:Adsorption; D000818:Animals; D049872:Bivalvia / Q000737:chemistry; D003979:Diazonium Compounds / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D054802:Molecular Imprinting / Q000379:methods*; D019319:Okadaic Acid / Q000032:analysis / Q000302:isolation & purification*; D012015:Reference Standards
chemical_list: D003979:Diazonium Compounds; D019319:Okadaic Acid