Impedimetric Detection of Pathogenic Gram-Positive Bacteria Using an Antimicrobial Peptide from Class IIa Bacteriocins

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• 作者：Hashem Etayash ; Keren Jiang ; Thomas Thundat ; Kamaljit Kaur
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：February 4, 2014
• 年：2014
• 卷：86
• 期：3
• 页码：1693-1700
• 全文大小：376K
• ISSN：1520-6882

文摘

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鈥揵acteria interactions at a concentration of 1 cell/渭L. The peptide sensor also selectively detected Listeria monocytogenes from other Gram-positive strains at a concentration of 10³ cfu mL^鈥?. 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.