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Foodborne pathogens pose significant risks to food safety. Conventional biochemical detection techniques are facing a series of challenges. In recent years, with the gradual development of CRISPR (clustered regularly interspaced short palindromic repeats) technology, CRISPR/Cas system-based biosensors, a newly emerging technology, have received much attention from researchers because of their supreme flexibility, sensitivity, and specificity. While numerous CRISPR-based biosensors have a broad application in the field of environmental monitoring, food safety, and point-of-care diagnosis, they remain in high demand to summarize recent advances in CRISPR/Cas system-based biosensors for foodborne pathogen detection. In this paper, we briefly classify and discuss the working principles of CRISPR/Cas systems with trans-cleavage activity in applications for the detection of foodborne pathogenic microorganisms. We highlight the current status, the unique feature of each CRISPR system and CRISPR-based biosensing platforms, and the integration of CRISPR-Cas with other techniques, concluding with a discussion of the advantages, disadvantages, and future directions. [ABSTRACT FROM AUTHOR]

Amantadine (AMA) is an illegally used antiviral drug in the poultry industry, it is necessary to establish a fast, accurate and time-saving detection method for poultry food. The antibody-based immunoassay can achieve fast and accurate requirements. We developed a recombinant antibody-based specificity immunoassay for AMA. In the recombinant antibody, the heavy chain variable region (VH) is connected covalently with the light chain variable region (VL) by the artificial linker. Here, two recombinant antibodies’ single-chain variable fragment (scFv) and scFv-dHLX were constructed and functionally expressed in the periplasm of Escherichia coli. The helix-turn-helix peptide was utilized to dimerize VH and VL similar to the IgG counterpart. The ScFv-dHLX protein showed a higher binding ability and affinity resulting in improvement of in vitro affinity activity over its corresponding scFv. Our results not only indicated scFv-dHLX as an alternative for scFv in analytical application, but also offered a novel and efficient hetero-dimerization pattern of VH and VL leading to enhanced affinity. [ABSTRACT FROM AUTHOR]

A competitive lateral flow immunoassay (LFA) using fluorescent microspheres (FMs) as label was developed for the quantitative detection of chloramphenicol (CAP), thiamphenicol (TAP) and florfenicol (FF) in milk. The limit of detection (LOD) for CAP, TAP and FF in milk was 0.08, 0.8 and 1.9 μg L−1, respectively. The recovery of intra and inter-assay ranged from 87.7% to 107.0% and 82.5% to 112.3%, with corresponding coefficient of variations less than 11.3% and 14.5%, respectively. The sensitivity of the FMs lateral flow assay (FMs-LFA) was comparable to those of the colloidal gold lateral flow assay. A quantitative comparison of the FMs-LFA and LC-MS/MS analysis of milk samples indicated good agreement between the two methods. The FMs-LFA can be used as a reliable, rapid and cost-effective method for food safety analysis. [ABSTRACT FROM AUTHOR]