title: Impedimetric detection of pathogenic Gram-positive bacteria using an antimicrobial peptide from class IIa bacteriocins.
abstract: Real-time, label-free detection of Gram-positive bacteria with high selectivity and sensitivity is demonstrated using an interdigitated impedimetric array functionalized with naturally produced antimicrobial peptide from class IIa bacteriocins. The antimicrobial peptide, leucocin A, was chemically synthesized and covalently immobilized on interdigitated gold microelectrodes via the interaction between the C-terminal carboxylic acid of the peptide and free amines of a preattached thiolated linker. Exposing the peptide sensor to various concentrations of Gram-positive bacteria generated reproducible impedance spectra that detected peptide-bacteria interactions at a concentration of 1 cell/μL. The peptide sensor also selectively detected Listeria monocytogenes from other Gram-positive strains at a concentration of 10(3) cfu mL(-1). The study highlights that short peptide ligands from bacteriocin class offer high selectivity in bacterial detection and can be used in developing a robust, portable biosensor device to efficiently detect pathogenic Gram-positive bacteria in food samples.
authors.affiliation: Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta , Edmonton, Alberta, T6G 2E1, Canada.
authors.forename: Hashem
authors.initials: H
authors.lastname: Etayash
authors.forename: Keren
authors.initials: K
authors.lastname: Jiang
authors.forename: Thomas
authors.initials: T
authors.lastname: Thundat
authors.forename: Kamaljit
authors.initials: K
authors.lastname: Kaur
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001430:Bacteriocins / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D058266:Dielectric Spectroscopy; D006094:Gram-Positive Bacteria / Q000302:isolation & purification*; D008892:Milk / Q000382:microbiology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D010446:Peptide Fragments