title: An amperometric affinity penicillin-binding protein magnetosensor for the detection of β-lactam antibiotics in milk.
abstract: The preparation, characterization and performance evaluation of an amperometric affinity disposable magnetosensor, based on the use of a recombinant penicillin-binding protein (PBP) and screen-printed carbon electrodes (SPCEs), for the specific detection and quantification of β-lactam antibiotic residues in milk are reported. The PBP was immobilized onto His-Tag-Isolation-modified magnetic beads (His-Tag-Isolation-MBs), and a direct competitive assay using a tracer with horseradish peroxidase (HRP) for the enzymatic labeling was performed. The amperometric response obtained at -0.20 V vs. the Ag pseudo-reference electrode of the SPCE after the addition of H2O2 in the presence of hydroquinone (HQ) was used as the transduction signal. The developed methodology showed very low detection limits (in the low ppb level) for the 6 antibiotics tested in untreated milk samples, and a good selectivity against other antibiotic residues frequently detected in milk and dairy products. Due to the bioreceptor employed, this methodology was able to detect only the active form of β-lactam antibiotics with high affinities for both penicillins and cephalosporins. Moreover, the analysis took only 30 min.
authors: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid, Spain.
authors: M
authors: M
authors: Gamella
authors: S
authors: S
authors: Campuzano
authors: F
authors: F
authors: Conzuelo
authors: M
authors: M
authors: Esteban-Torres
authors: B
authors: B
authors: de las Rivas
authors: A J
authors: AJ
authors: Reviejo
authors: R
authors: R
authors: Muñoz
authors: J M
authors: JM
authors: Pingarrón
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D002417:Cattle; D002511:Cephalosporins / Q000032:analysis; D004350:Drug Residues / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D008280:Magnetics; D008892:Milk / Q000737:chemistry*; D046915:Penicillin-Binding Proteins / Q000737:chemistry*; D010406:Penicillins / Q000032:analysis; D047090:beta-Lactams / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D047090:beta-Lactams