Development of Latex Microsphere-Based Immunochromatographic Strips for Detecting Key Aflatoxins

Due to the severe hazard of aflatoxins (AFs) to humans, it is of great significance to detect the key aflatoxins, aflatoxin B1(AFB1) and aflatoxin G1(AFG1), in food and feed in simple, rapid, and semi-quantitative ways. The hybridoma clone 3A1 was prepared in this study, and anti-AFB1monoclonal antibody (mAb) with high specificity and affinity (9.38 × 108L/mol) from 3A1 was purified. The indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) demonstrated that the linear detection range for AFB1was 0.029–1.526 ng/mL with a limits of determination (LOD) of 0.023 ng/mL. A latex microsphere-based immunochromatographic test strip (LM-ICTS) was constructed based on 3A1, which showed that the strip could detect AFB1(LOD: lower than 1.79 ng/mL) and AFG1(LOD: lower than 8.08 ng/mL), and the linear detection ranges for AFB1and AFG1are 1.79–48.46 ng/mL and 8.08–107.40 ng/mL, respectively. The average recoveries of intra-assay and inter-assay for peanuts were (98.4 ± 4.7)% and (92.6 ± 7.6)%, and the average coefficient of variation (CVs) were 4.38% and 8.15%, respectively. For sunflower seeds, the intra-assay and inter-assay recoveries were (94.4 ± 7.2)% and (89.2 ± 4.3)%, and the average CVs were 6.6% and 4.9%, respectively. In summary, the developed LM-ICTS exhibited excellent sensitivity and specificity, which provided a rapidly stable on-site detection choice for AFB1and AFG1to contaminated agricultural samples, including grain and feed.