An ELISA-on-a-Chip Biosensor System for Early Screening of Listeria monocytogenes in Contaminated Food Products

Abstract

An enzyme-linked immunosorbent assay (ELISA)-on-a-chip (EOC) biosensor combined with cell concentration technology based on immuno-magnetic separation (IMS) was investigated for use as a potential tool for early screening of Listeria monocytogenes (L. monocytogenes) in food products. The target analyte is a well-known pathogenic foodborne microorganism and outbreaks of the food poisoning typically occur due to contamination of normal food products. Thus, the aim of this study was to develop a rapid and reliable sensor that could be utilized on a daily basis to test food products for the presence of this pathogenic microorganism. The sensor was optimized to provide a high detection capability (e.g., 5.9 × 10 3 cells/mL) and, to eventually minimize cultivation time. The cell density was condensed using IMS prior to analysis. Since the concentration rate of IMS was greater than 100-fold, this combination resulted in a detection limit of 54 cells/mL. The EOC-IMS coupled analytical system was then applied to a real sample test of fish intestines. The system was able to detect L. monocytogenes at a concentration of 2.4 CFU/g after pre-enrichment for 6 h from the onset of cell cultivation. This may allow us to monitor the target analyte at a concentration less than 1 CFU/g within a 9 h-cultivation provided a doubling time of 40 min is typically maintained. Based on this estimation, the EOC-IMS system can screen and detect the presence of this microorganism in food products almost within working hours.

Actuation of chitosan-aptamer nanobrush borders for pathogen sensing

“…66 are rapid (including loop-mediated isothermal amplification or LAMP), with total analysis time of less than one hour, but with poor LOD values near 10 2 CFU-mL -1 . The LOD can be improved considerably with sample pretreatment 67 , but this adds to the analysis time, which is not desirable in a food processing environment.…”

Planar Interdigitated Aptasensor for Flow-Through Detection of Listeria spp. in Hydroponic Lettuce Growth Media

“…For example, the aptamer sandwich assay developed by Lee et al [ 68 ] presented an LOD of 20 CFU mL −1 but a response time of 2 h in buffer. The lowest LOD for colorimetric sensors was 2.4 CFU mL −1 , but it required 6.5 h in buffer [ 19 ]. Few SPR-based devices for Listeria detection are found in the literature, but Boulade et al [ 69 ] recently reported a SPR-based device with a LOD of 2 × 10 2 CFU mL −1 after 7 h.…”

“…For instance, Listeria monocytogenes is the bacteria responsible for listeriosis, the third leading cause of death from food poisoning [ 11 , 12 ]. Given the transient nature of Listeria in the food chain, a variety of sensors and biosensors have been developed in the last few decades to monitor pathogens associated with food safety [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

Immunomagnetic separation: An effective pretreatment technology for isolation and enrichment in food microorganisms detection

“…The monoclonal antibody was conjugated to the amine groups modified MPs to get IMPs, which were then blocked by PBS containing 0.5% casein to improve specificity. On the basis of IMS, the concentration of L. monocytogenes was improved more than 100 times and the detection limit of ELISA‐on‐a‐chip biosensor was as low as 54 cells/mL (Seo et al., 2009). IMPs were prepared by combining magnetic beads (M‐280) with monoclonal antibody via the streptavidin‐biotin reaction for the separation of L. monocytogenes in meat.…”