Analytical and Bioanalytical Chemistry

, Volume 403, Issue 4, pp 917–925

Sensitive and rapid amperometric magnetoimmunosensor for the determination of Staphylococcus aureus

  • Berta Esteban-Fernández de Ávila
  • María Pedrero
  • Susana Campuzano
  • Vanessa Escamilla-Gómez
  • José M. Pingarrón
Original Paper

DOI: 10.1007/s00216-012-5738-8

Cite this article as:
Esteban-Fernández de Ávila, B., Pedrero, M., Campuzano, S. et al. Anal Bioanal Chem (2012) 403: 917. doi:10.1007/s00216-012-5738-8

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.

Figure

Schematic display of the developed S. aureus amperometric magnetoimmunosensor

Keywords

Electrochemical magnetoimmunosensor Protein A Staphylococcus aureus Raw milk 

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Berta Esteban-Fernández de Ávila
    • 1
  • María Pedrero
    • 1
  • Susana Campuzano
    • 1
  • Vanessa Escamilla-Gómez
    • 1
  • José M. Pingarrón
    • 1
  1. 1.Departamento de Química Analítica, Facultad de CC. QuímicasUniversidad Complutense de MadridMadridSpain

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