Sensitive and portable intelligent detection of imidacloprid in agricultural products using smartphone‐integrated test strips

Abstract The detection rate of imidacloprid (IMI) in agro‐products are increasing annually, posing negative effects on food safety and human health. A sensitive and portable dual‐mode lateral flow immunoassay (LFIA) method, combined with the smartphone, has been established to monitor the IMI residues in agro‐products. Optimal detection conditions were achieved with 0.4 mg/mL of IMI coating antigen and 4 μg/mL of IMI monoclonal antibody. The limit of detection (LOD) for qualitative analysis with naked‐eye observation was determined to be 25 ng/mL. For quantitative analysis, 20% inhibition concentration (IC 20 ) was found to be 2.55 ng/mL, with a linear range (IC 20 –IC 80 ) of 2.55–26.94 ng/mL. The recoveries and relative standard deviation (RSD) were in the ranges of 90.4%–103.2% and 2.0%–11.7%, respectively. There was a strong agreement between the results obtained from the established method and those from UHPLC‐MS/MS, with the slope and coefficient of determination ( R 2 ) reaching to 1.091 and 0.9837, respectively. Overall, the proposed dual‐mode LFIA method provides an efficient approach for on‐site detection of IMI in agro‐products.