A bacteriophage endolysin-based electrochemical impedance biosensor for the rapid detection of Listeria cells

Analyst. 2012 Dec 21;137(24):5749-56. doi: 10.1039/c2an35988j.

Abstract

The objective of this study was to develop a biosensor using the cell wall binding domain (CBD) of bacteriophage-encoded peptidoglycan hydrolases (endolysin) immobilized on a gold screen printed electrode (SPE) and subsequent electrochemical impedance spectroscopy (EIS) for a rapid and specific detection of Listeria cells. The endolysin was amine-coupled to SPEs using EDC/NHS chemistry. The CBD-based electrode was used to capture and detect the Listeria innocua serovar 6b from pure culture and 2% artificially contaminated milk. In our study, the endolysin functionalized SPEs have been characterized using X-ray photoelectron spectroscopy (XPS). The integration of endolysin-based recognition for specific bacteria and EIS can be used for direct and rapid detection of Listeria cells with high specificity against non-Listeria cells with a limit of detection of 1.1 × 10(4) and 10(5) CFU mL(-1) in pure culture and 2% milk, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriophages / enzymology*
  • Biosensing Techniques / methods*
  • Cell Wall / metabolism
  • Dielectric Spectroscopy*
  • Electrochemistry
  • Endopeptidases / chemistry*
  • Endopeptidases / metabolism*
  • Enzymes, Immobilized / chemistry
  • Enzymes, Immobilized / metabolism
  • Gold / chemistry
  • Listeria / cytology*
  • Listeria / isolation & purification
  • Protein Structure, Tertiary
  • Surface Properties
  • Time Factors

Substances

  • Enzymes, Immobilized
  • Gold
  • Endopeptidases
  • endolysin