Simultaneous detection of two herbicides in fruits and vegetables with nanoparticle-linked immunosorbent and lateral flow immunoassays

Herbicides atrazine and acetochlor are used in crop production. Because of environmental and health hazards with respective maximum contamination levels of 3 and 20 ng/mL, quantifying these herbicides is important when considering presence in foods and vegetables. We utilized two Pd@Pt nanoparticle-amplified immunoassays, a colorimetric Pd@Pt nanoparticle-linked immunosorbent assay (NLISA) and differential pulse voltammetry (DPV) dependent on catalytic activity of Pd@Pt in a dual-lateral flow immunoassay (dual-LFIA-DPV). We achieved overall recoveries of 88.5-114 % in juice, fruit, and vegetable samples for both immunoassays. The NLISA yielded limits of detection (LODs) of 0.59 and 0.31 µg/kg and the dual-LFIA-DPV 0.27 and 0.51 µg/kg for the two respective species. Results for both immunoassays were validated by high-performance liquid chromatography (HPLC), for all food and drink samples though LODs are compromised when configuring the HPLC for both species with the same chromatogram. We expect Pd@Pt-based immunoassays to prove useful in various fields.