title: Sensitive and selective magnetoimmunosensing platform for determination of the food allergen Ara h 1.
abstract: A highly sensitive disposable amperometric immunosensor based on the use of magnetic beads (MBs) is described for determination of Ara h 1, the major peanut allergen, in only 2h. The approach uses a sandwich configuration involving selective capture and biotinylated detector antibodies and carboxylic acid-modified MBs (HOOC-MBs). The MBs bearing the immunoconjugates are captured by a magnet placed under the surface of a disposable screen-printed carbon electrode (SPCE) and the affinity reactions are monitored amperometrically at -0.20 V (vs a Ag pseudo-reference electrode) in the presence of hydroquinone (HQ) as electron transfer mediator and upon addition of H2O2 as the enzyme substrate. The developed immunosensor exhibits a wide range of linearity between 20.8 and 1000.0 ng mL(-1) Ara h 1, a detection limit of 6.3 ng mL(-1), a great selectivity, a good reproducibility with a RSD of 6.3% for six different immunosensors and a useful lifetime of 25 days. The usefulness of the immunosensor was demonstrated by determining Ara h 1 in different matrices (food extracts and saliva). The results correlated properly with those provided by a commercial ELISA method offering a reliable and promising analytical screening tool in the development of user-friendly devices for on-site determination of Ara h 1.
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: victor_lega90@hotmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Ruiz-Valdepeñas Montiel
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: susanacr@quim.ucm.es.
authors.forename: S
authors.initials: S
authors.lastname: Campuzano
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DEFENS), University of Milan, Via Celoria 2, 20133 Milan, Italy. Electronic address: alessandro.pellicano@unimi.it.
authors.forename: A
authors.initials: A
authors.lastname: Pellicanò
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: rebeca.magnolia@gmail.com.
authors.forename: R M
authors.initials: RM
authors.lastname: Torrente-Rodríguez
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: reviejo@quim.ucm.es.
authors.forename: A J
authors.initials: AJ
authors.lastname: Reviejo
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DEFENS), University of Milan, Via Celoria 2, 20133 Milan, Italy. Electronic address: stella.cosio@unimi.it.
authors.forename: M S
authors.initials: MS
authors.lastname: Cosio
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: pingarro@quim.ucm.es.
authors.forename: J M
authors.initials: JM
authors.lastname: Pingarrón
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D052179:Antigens, Plant / Q000032:analysis* / Q000276:immunology; D015374:Biosensing Techniques; D001710:Biotin / Q000737:chemistry; D019921:Biotinylation; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D006023:Glycoproteins / Q000032:analysis* / Q000276:immunology; D006861:Hydrogen Peroxide / Q000737:chemistry; D006873:Hydroquinones / Q000737:chemistry; D018796:Immunoconjugates / Q000737:chemistry / Q000276:immunology; D057230:Limit of Detection; D008280:Magnetics; D008565:Membrane Proteins; D010940:Plant Proteins / Q000032:analysis* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; D006023:Glycoproteins; D006873:Hydroquinones; D018796:Immunoconjugates; D008565:Membrane Proteins; D010940:Plant Proteins; D001710:Biotin; D006861:Hydrogen Peroxide; C031927:hydroquinone
keywords: Amperometric immunosensor; Ara h 1; Food extracts; Magnetic beads; Saliva; Screen-printed electrode