Comparison of 4 label-based immunochromatographic assays for the detection of Escherichia coli O157:H7 in milk

Abstract

Immunochromatographic assays (ICA) are widely used to detect pathogens. In this study, we used traditional gold nanoparticles (GNP), quantum dots (QD), fluorescent nanoparticles (FNP), and europium (Eu) (III) chelate nanoparticles (EuNP) as ICA labels. We first compared the ability of the 4 ICA test strips to quantitatively detect Escherichia coli O157:H7 in milk. We then optimized various parameters influencing the ICA. The sensitivity to E. coli O157:H7 of the GNP-ICA, QD-ICA, FNP-ICA, and EuNP-ICA was 2.5 × 10, 5 × 10, 1.0 × 10, and 5.0 × 10 cfu mL, respectively. The EuNP-ICA exhibited the highest sensitivity. The amounts of monoclonal antibodies (mAb) per GNP-ICA, QD-ICA, FNP-ICA, and EuNP-ICA test strip were 0.16, 0.37, 0.04, and 0.10 μg, respectively. The corresponding coefficients of variation were 7.4 to 15.8%, 10.4 to 18.6%, 2.7 to 7.8%, and 6.9 to 10.5%, respectively. The FNP-ICA required the least mAb per test strip and had the best coefficient of variation. The linear ranges of GNP-ICA, QD-ICA, FNP-ICA, and EuNP-ICA were 1.0 × 10 to 1.0 × 10, 2.5 × 10 to 1.0 × 10, 2.5 × 10 to 2.5 × 10, and 2.5 × 10 to 2.5 × 10 cfu mL, respectively. The FNP-ICA and EuNP-ICA had wider linear ranges than GNP-ICA and QD-ICA. Additionally, the FNP-ICA and EuNP-ICA showed better tolerance than GNP-ICA and QD-ICA in the milk samples. The FNP-ICA and EuNP-ICA showed remarkable potential for detection of pathogens in milk.

Functionalized AuMBA@Ag Nanoparticles as an Optical and SERS Dual Probe in a Lateral Flow Strip for the Quantitative Detection of Escherichia coli O157:H7

“…E. coli O157:H7 can contaminate water and food (Huang, Zhao, & Dou, ) and cause hemolytic uremic syndrome, bloody diarrhea, and even death (Pang et al., ). The World Health Organization has emphasized the significance of control and prevention of the spread of E. coli O157:H7 associated with food consumption (Luo et al., ). Therefore, sensitive and rapid detection of E. coli O157:H7 is crucial to ensure the health of consumers.…”

Rapid quantification of coliforms in ready‐to‐eat foods using lateral‐flow immunochromatographic assay

“…A number of attempts have been made to quantify analytes from the concentration of labeling agent accumulating on the strip (Dzantiev, Byzova, Urusov, & Zherdev, 2014). E. coli O157 was quantified using LFIA with Au NPs, quantum dots, fluorescein isothiocyanate fluorescent NPs, or EuNPs as a labeling agent (Luo et al, 2017). Vibrio anguillarum was quantified in the range of 10 3 –10 9 cfu/ml using up‐converting phosphors as a labeling agent (Zhao et al, 2014) in addition to Listeria monocytogenes and Salmonella Typhimurium in the range of 10 2 –10 7 cfu/ml with the aid of the Raman microscope system after LFIA (Wu, 2019).…”

Comparative Study of Time-Resolved Fluorescent Nanobeads, Quantum Dot Nanobeads and Quantum Dots as Labels in Fluorescence Immunochromatography for Detection of Aflatoxin B1 in Grains

“…Carboxylated quantum dot nanobeads (QB, 1 uM, w/v, excitation = 365 nm, emission = 610 nm) and quantum dots (QD, 1.0 mg/mL, w/v; carboxylate-modified CdSe/ZnS core/shell nanocrystals with amphiphilic polymer coating; excitation Although many methods based on immune interactions have been developed for the detection of toxic and harmful substances, it is impossible to compare the performance of those methods for identifying the most appropriate approach due to the utilization of distinct antibodies/antigens, markers and the detection conditions. In recent years, only a few reports have used comparative methods under the same conditions [26][27][28][29][30][31]. For instance, Xie et al [27] established flow immunochromatography to detect Escherichia coli O157:H7 in milk, in which fluorescent microspheres and colloidal gold were compared in terms of antibody labeling efficiency, sensitivity, antibody consumption and coefficient of variation.…”