Detection of <i>Listeria Monocytogenes</i> by Electrochemical Impedance Spectroscopy

Abstract

Abstract Listeria monocytogenes is detected by electrochemical impedance spectroscopy using a mouse monoclonal antibody immobilized onto an Au electrode. This yields sensitivities of 0.825 kΩ cm 2 /(CFU/mL) and 1.129 kΩ cm 2 /(CFU/mL) and detection limits of 5 CFU/mL and 4 CFU/mL for ideal solutions and filtered tomato extract, respectively. Control experiments with an Au electrode onto which a mouse monoclonal antibody to GAPDH is immobilized demonstrate that non‐specific adsorption is insignificant for the system and methodology studied here. Control experiments with Salmonella enterica demonstrate no cross‐reactivity to this food pathogen. Potential technological hurdles to development of a multiplexed impedance biosensor for food pathogens are also discussed.