title: Immunorecognition magnetic supports for the development of an electrochemical immunoassay for azaspiracid detection in mussels.
abstract: As azaspiracids (AZAs) are being reported from the coastal waters of an increasing number of countries on a global scale, the need for rapid, simple and cost-effective methods to detect these marine toxins and protect seafood consumers' health is becoming evident. A magnetic bead (MB)-based direct immunoassay for the detection of AZAs, using protein G-coated MBs as supports for antibody immobilisation and peroxidase-labelled AZA as a tracer is detailed. A colorimetric approach was first developed to optimise the experimental parameters and establish the cross-reactivity factors for AZA-1-10. The subsequent combination of the immunorecognition MBs with 8-electrode arrays enabled the multiplexed electrochemical detection of AZAs. Naturally-contaminated mussel samples were analysed and the results obtained showed an excellent correlation with LC-MS/MS analysis. The MB-based immunoassay facilitated the quantification of a wide range of AZA concentrations (120-2875μg AZA-1 equiv./kg), with a limit of detection (63μg AZA-1 equiv./kg) below the European regulatory threshold, using a protocol that requires very few steps and a short analysis time (~ 15min). The simplicity, cost-effectiveness, rapidity, robustness, selectivity and precision of the assay provide a valuable tool for the detection of all regulated AZAs and other toxic AZA analogues, suitable for end users in the field of food safety.
authors.affiliation: IRTA, Ctra. Poble Nou, km. 5.5, 43540 Sant Carles de la Ràpita, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Leonardo
authors.affiliation: IRTA, Ctra. Poble Nou, km. 5.5, 43540 Sant Carles de la Ràpita, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Rambla-Alegre
authors.affiliation: Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway.
authors.forename: Ingunn A
authors.initials: IA
authors.lastname: Samdal
authors.affiliation: Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway.
authors.forename: Christopher O
authors.initials: CO
authors.lastname: Miles
authors.affiliation: Marine Institute, Rinville, Oranmore, County Galway H91 R673, Ireland.
authors.forename: Jane
authors.initials: J
authors.lastname: Kilcoyne
authors.affiliation: IRTA, Ctra. Poble Nou, km. 5.5, 43540 Sant Carles de la Ràpita, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Diogène
authors.affiliation: Departament d'Enginyeria Química, Universitat Rovira i Virgili, Av. Països Catalans, 26, 43007 Tarragona, Spain; Institució Catalana de Recerca i Estudis Avançats, Pg. Lluís Companys, 23, 08010 Barcelona, Spain.
authors.forename: Ciara K
authors.initials: CK
authors.lastname: O'Sullivan
authors.affiliation: IRTA, Ctra. Poble Nou, km. 5.5, 43540 Sant Carles de la Ràpita, Spain. Electronic address: monica.campas@irta.cat.
authors.forename: Mònica
authors.initials: M
authors.lastname: Campàs
mesh_terms: D000818:Animals; D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods; D049872:Bivalvia / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D008387:Marine Toxins / Q000032:analysis*; D017747:Seafood / Q000032:analysis*; D013141:Spiro Compounds / Q000032:analysis*; D000095702:Polyether Toxins
chemical_list: D055910:Antibodies, Immobilized; D008387:Marine Toxins; D013141:Spiro Compounds; C406592:azaspiracid; D000095702:Polyether Toxins
keywords: Azaspiracid; Electrochemical; Horseradish peroxidase; Immunoassay; Magnetic bead; Mussel