Lateral flow immunoassay integrated with competitive and sandwich models for the detection of aflatoxin M1 and Escherichia coli O157:H7 in milk

Abstract

Pathogens, mycotoxins, or antibiotics may exist in a food sample. Micro- and macromolecular substances must be detected quickly. A rapid and convenient lateral flow immunoassay (LFI) integrated with competitive and sandwich models was developed to detect micro- and macromolecular substances. In this study, aflatoxin M (AFM) and Escherichia coli O157:H7 were selected as the micro- and macromolecular substances, respectively. Two test lines in the LFI test strip were evaluated to detect AFM1 and E. coli O157:H7 by competitive and sandwich models. Results showed that the limits of detection for detecting AFM1 and E. coli O157:H7 were 50 pg·mL and 1.58 × 10 cfu·mL, respectively. The whole assay time was 30 min. The recoveries of gold nanoparticle-LFI ranged from 78.0 to 111.6% with coefficients of variation in the range of 3.9 to 8.5% for the detection of AFM. For the detection of E. coli O157:H7, the range of recoveries was from 70.1 to 89.6% with coefficients of variation ranging from 4.9 to 13.0%. This study not only tested sensitivity and specificity, but also was a systematic study of location of 2 test lines of the LFI test strip integrated with competitive and sandwich models.

A Sensitive Two-Analyte Immunochromatographic Strip for Simultaneously Detecting Aflatoxin M1 and Chloramphenicol in Milk

“…The previous study found that the signal at the test line close to the sample pad was stronger than that farther from the sample pad [ 26 ]. However, in this work, the test line close to the sample pad was less sensitive than that which was away from the sample pad.…”

Point-of-Need Diagnostics for Foodborne Pathogen Screening

“…A negative test is indicated by the appearance of only the control line. Early versions of this LFA have proven that the assay can specifically detect the presence of foodborne pathogens in milk, 26,27 bread, 27 and raw beef 28 both with and without prior enrichment. Furthermore, the low cost, portability, rapid time to detection, ease of use, and long shelf life make them ideal for use in PON settings.…”

Preparasi Strip Imunokromatografi Koloid Emas untuk Deteksi Cepat Aeromonas hydrophila

“…Pengembangan strip imunokromatografi pada penelitian ini menggunakan model sandwich. Strip imunokromatografi ini sangat cocok digunakan untuk mendeteksi target berupa makromolekul seperti protein dan memiliki beberapa epitope (Wang et al, 2018). Konsentrasi antibodi goat antirabbit IgG 1 mg/ml di garis C dan antibodi anti A. hydrophila 2 mg/ml di garis T diaplikasikan pada membran nitroselulosa pada penelitian ini.…”