Juan Peng,Shanshan Song,Liguang Xu,Wei Ma,Liqiang Liu,Hua Kuang,Chuanlai Xu
We have established a highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA) based on two monoclonal antibodies (mAb) to measure the content of the major peanut allergen Ara h 1 in foods. Two mAbs were selected out of 12 murine hybridoma cells secreting Ara h 1-specific antibody. Using mAb 6 as the capture antibody and HRP-labelled mAb 4 as the detection antibody, the limit of detection (LOD) the assay was 0.34 ng/mL. Cross-reaction analysis showed that this method was strongly specific and had no cross-reactions with Ara h 2, pea protein or soy protein. Sample analysis showed that this ELISA was a useful tool to monitor peanut allergens in food products by measuring Ara h 1 content.Keywords:peanut allergen;Ara h 1;monoclonal antibody;sandwich ELISA
A portable biosensor for the peanut allergen Ara h 1 was developed by integrating a polydopamine-functionalized pipette tip, CRISPR/Cas12a signal amplification, and a personal glucose meter. Ara h 1 binding induced partial displacement of a cDNA activator, which activated Cas12a trans-cleavage and released glucose oxidase from GOx–DNA conjugates. The released enzyme catalyzed glucose oxidation, producing a quantitative decrease in glucose concentration. Under optimized conditions, the assay showed a linear range of 50–1000 ng/mL and a solution-based limit of detection of 22.19 ng/mL. Post-extraction matrix-spike tests in commercial peanut-biscuit and peanut-beverage extracts yielded recoveries of 101.58–104.68% with relative standard deviations below 3.44%. These results demonstrate the analytical feasibility and preliminary matrix compatibility of the platform, although validation using pre-extraction fortified, incurred, and naturally contaminated foods is still required.