Rapid determination of amygdalin in almonds and almond-based products using lateral flow immunoassay based on gold nanoparticles

Amygdalin is a phytotoxin that releases hydrocyanic acid, a highly toxic substance, under the action of enzymes or acids, posing a threat to human health. In this study, a highly sensitive and specific monoclonal antibody (mAb) 3D11, with a half-maximal inhibitory concentration of 0.66 ng/mL, was developed through similarity calculation and molecular structure, molecular spatial overlap, electrostatic potential distribution, and HOMO-LUMO orbitals analyses of hapten design principles. A gold nanoparticle-based lateral flow immunoassay (GNP-LFIA) was developed to detect amygdalin in almonds and almond-based products, with a visual detection limit of 2–10 μg/kg and a detection limit of 0.27–1.27 μg/kg. The recoveries of GNP-LFIA ranged from 94.02 % to 109.50 %, and the accuracy and reliability were further confirmed by testing positive samples, demonstrating that GNP-LFIA can be a practical tool for the rapid on-site detection of amygdalin in almonds and almond-based products.