Electrochemical Detection of Salmonella and Listeria with Functionalized Magnetic Nanoparticles

Contaminated food, particularly by food-borne pathogens such as Salmonella and Listeria, represents
a significant global public health challenge, leading to severe gastrointestinal illnesses and thousands of fatalities
annually [1]. Traditional pathogen detection methods are labor-intensive, time-consuming, and require
specialized equipment and trained personnel. Rapid and accurate pathogen detection on site is vital for ensuring
environmental and food safety and consequently public health. Electrochemical detection using gold electrodes
with magnetic nanoparticles offers a promising platform for rapid and sensitive pathogen detection which allows
incorporation of pre-concentration step as well. By functionalizing magnetic nanoparticles with specific aptamers
or antibodies, this method achieves high specificity for targeted pathogens, without the the necessity of direct
biomolecule immobilization onto the electrode. This study presents an innovative approach utilizing
nanoparticles functionalized with aptamers to detect Listeria and Salmonella on a low-cost gold leaf
electrochemical transducing platform [2]. Electrochemical impedance spectroscopy (EIS) was used to detect
varying bacterial concentrations in both, buffer and complex matrices. The developed sensor demonstrated
specific recognition of Listeria and Salmonella, achieving a detection limit of 10¹ cfu/mL. The results demonstrate
a clear and linear increase in impedance with rising bacterial concentrations, confirming the sensitivity and
effectiveness of the platform.
[1] World Health Organization, Gobal strategy for food safety 2022-2030: towards stronger food safety systems and
global cooperation, WHO, 2022.
[2] I. Podunavac, M. Kukkar, V. Léguillier, F. Rizzotto, Z. Pavlovic, Lj. Janjušević, V. Costache, V. Radonic, J. Vidic.
2023, Low-cost goldleaf electrode as a platform for Escherichia coli immunodetection, Talanta 259.
doi:10.1016/j.talanta.2023.124557