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Published on: June 28, 2024
Fluorescence immunoassay for the targeted determination of trace Listeria monocytogenes based on immunomagnetic
Shan Liang1, Li Ji1, Yingying Zhong1
1Department of Pharmaceutical Engineering, School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, People's Republic of China. qlli19@gdut.edu.cn.
Insights
A new fluorescence immunoassay accurately detects trace Listeria monocytogenes in food. This method uses antibody-functionalized nanoparticles and quantum dots for sensitive and rapid food safety testing.
Area of Science:
- Food Safety
- Analytical Chemistry
- Biotechnology
Background:
- Invasive Listeria monocytogenes infections pose significant public health risks due to high morbidity and mortality.
- Sensitive, specific, and rapid detection of L. monocytogenes is crucial for food safety and preventing outbreaks.
Purpose of the Study:
- To develop a highly sensitive and specific fluorescence immunoassay for detecting trace amounts of L. monocytogenes.
- To create a rapid detection method for L. monocytogenes in food matrices.
Main Methods:
- Fabrication of a fluorescence immunoassay using guinea pig antibody-functionalized magnetic nanoparticles (Fe3O4 NPs/pAb1) and rabbit antibody-anchored CdZnTe quantum dots (CdZnTe QDs/pAb2).
- Utilized antibody-directed magnetic separation and long-wave fluorescent emission from CdZnTe QDs for detection.
- Tested the immunosensor's performance with spiked tap water and pasteurized milk samples.
Main Results:
- The immunosensor demonstrated excellent anti-interference performance in biological matrices.
- Achieved a wide detection range from 1 to 10^9 CFU mL^-1 for L. monocytogenes.
- Exhibited a low limit of detection (LOD) of 1 CFU mL^-1, indicating exceptional sensitivity.
- Showcased good specificity and a rapid detection time of 60 minutes.
Conclusions:
- The developed fluorescence immunoassay offers a sensitive, specific, and rapid method for detecting trace L. monocytogenes.
- This approach significantly enhances food safety and public health monitoring capabilities.
- The immunosensor's performance in real-world samples (tap water, pasteurized milk) validates its practical applicability.
Abstract:
Infections from invasive Listeria monocytogenes (L. monocytogenes) frequently occur in food and can cause high morbidity and death. Thus, the sensitive, specific, and rapid detection of L. monocytogenes is critical for ensuring food safety and public health. Herein, a fluorescence immunoassay for trace L. monocytogenes detection was designed based on guinea pig antibody-functionalized magnetic nanoparticles (Fe3O4 NPs/pAb1) and rabbit antibody-anchored CdZnTe quantum dots (CdZnTe QDs/pAb2). Because of the antibody-directed magnetic separation and long-wave fluorescent emission for CdZnTe QD indication, the constructed immunoassay strategy presented excellent anti-interference performance toward a biological matrix. The immunosensor exhibited a wide detection range of 1 to 109 CFU mL-1 for L. monocytogenes and a low limit of detection (LOD) of 1 CFU mL-1, achieving an exceptionally sensitive detection of trace L. monocytogenes. Meanwhile, the immunosensor showed good specificity and had a short time-consumption of 60 min to realize the accurate determination of trace Listeria monocytogenes in spiked tap water and pasteurized milk samples.
