title: A bacteriophage endolysin-based electrochemical impedance biosensor for the rapid detection of Listeria cells.
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.
authors.affiliation: Institut National de la Recherche Scientifique-Énergie Matériaux Télécommunications, 1650 Boulevard Lionel-Boulet, Varennes, J3X1S2, Quebec, Canada.
authors.forename: Mona
authors.initials: M
authors.lastname: Tolba
authors.forename: Minhaz Uddin
authors.initials: MU
authors.lastname: Ahmed
authors.forename: Chaker
authors.initials: C
authors.lastname: Tlili
authors.forename: Fritz
authors.initials: F
authors.lastname: Eichenseher
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Loessner
authors.forename: Mohammed
authors.initials: M
authors.lastname: Zourob
mesh_terms: D001435:Bacteriophages / Q000201:enzymology*; D015374:Biosensing Techniques / Q000379:methods*; D002473:Cell Wall / Q000378:metabolism; D058266:Dielectric Spectroscopy; D004563:Electrochemistry; D010450:Endopeptidases / Q000737:chemistry* / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D008087:Listeria / Q000166:cytology* / Q000302:isolation & purification; D017434:Protein Structure, Tertiary; D013499:Surface Properties; D013997:Time Factors
chemical_list: D004800:Enzymes, Immobilized; D006046:Gold; D010450:Endopeptidases; C001143:endolysin