title: Sensitive and rapid amperometric magnetoimmunosensor for the determination of Staphylococcus aureus.
abstract: The preparation and characteristics of a disposable amperometric magnetoimmunosensor, based on the use of functionalized magnetic beads (MBs) and gold screen-printed electrodes (Au/SPEs), for the specific detection and quantification of Staphylococcal protein A (ProtA) and Staphylococcus aureus (S. aureus) is reported. An antiProtA antibody was immobilized onto ProtA-modified MBs, and a competitive immunoassay involving ProtA antigen labelled with HRP was performed. The resulting modified MBs were captured by a magnetic field on the surface of tetrathiafulvalene-modified Au/SPEs and the amperometric response obtained at -0.15 V vs the silver pseudo-reference electrode of the Au/SPEs after the addition of H2O2 was used as transduction signal. The developed methodology showed very low limits of detection (1 cfu S. aureus/mL of raw milk samples), and a good selectivity against the most commonly involved foodborne pathogens originating from milk. These features, together with a short analysis time (2 h), 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: Berta
authors.initials: B
authors.lastname: Esteban-Fernández de Ávila
authors.forename: María
authors.initials: M
authors.lastname: Pedrero
authors.forename: Susana
authors.initials: S
authors.lastname: Campuzano
authors.forename: Vanessa
authors.initials: V
authors.lastname: Escamilla-Gómez
authors.forename: José M
authors.initials: JM
authors.lastname: Pingarrón
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002417:Cattle; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D008280:Magnetics / Q000379:methods*; D008892:Milk / Q000737:chemistry / Q000382:microbiology; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology*; D013205:Staphylococcal Protein A / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000907:Antibodies, Bacterial; D013205:Staphylococcal Protein A