title: Disposable and integrated amperometric immunosensor for direct determination of sulfonamide antibiotics in milk.
abstract: The preparation and performance of a disposable amperometric immunosensor, based on the use of a selective capture antibody and screen-printed carbon electrodes (SPCEs), for the specific detection and quantification of sulfonamide residues in milk is reported. The antibody was covalently immobilized onto a 4-aminobenzoic acid (4-ABA) film grafted on the disposable electrode, and a direct competitive immunoassay using a tracer with horseradish peroxidase (HRP) for the enzymatic labeling was performed. The amperometric response measured at -0.2 V vs the silver pseudo-reference electrode of the SPCE upon the addition of H(2)O(2) in the presence of hydroquinone (HQ) as mediator was used as transduction signal. The developed methodology showed very low limits of detection (in the low ppb level) for 6 sulfonamide antibiotics tested in untreated milk samples, and a good selectivity against other families of antibiotics residues frequently detected in milk and dairy products. These features, together with the short analysis time (30 min), the simplicity, and easy automation and miniaturization of the required instrumentation make the developed methodology a promising alternative in the development of devices for on-site analysis.
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: Conzuelo
authors.forename: María
authors.initials: M
authors.lastname: Gamella
authors.forename: Susana
authors.initials: S
authors.lastname: Campuzano
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Pinacho
authors.forename: A Julio
authors.initials: AJ
authors.lastname: Reviejo
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Marco
authors.forename: José M
authors.initials: JM
authors.lastname: Pingarrón
mesh_terms: D010129:4-Aminobenzoic Acid / Q000737:chemistry; D000818:Animals; D000906:Antibodies / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006735:Horseradish Peroxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006873:Hydroquinones / Q000737:chemistry; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D013449:Sulfonamides / Q000032:analysis*
chemical_list: D000906:Antibodies; D006873:Hydroquinones; D013449:Sulfonamides; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D010129:4-Aminobenzoic Acid; C031927:hydroquinone