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Deoxynivalenol (DON) contamination of food crops and feeds is almost impossible to avoid completely; however, through best management practices, this risk can be effectively managed and maximumly mitigated. Accurate and rapid detection of DON contamination as early in the entire value chain as possible is critical. To achieve this goal, we developed a DON test strip based on time-resolved fluorescence immunoassay (TRFIA) and a specific DON monoclonal antibody for the rapid quantification of DON in food crops and feeds. The strip displayed a good linearity (R2 = 0.9926), with a limit of quantification of 28.16 μg/kg, a wide linear range of 50 ~ 10,000 μg/kg. The intra-batch coefficient of variation (CV) and the inter-batch CV was <5.00 and 6.60%, respectively. This TRFIA-DON test strip was applied to detect DON in real samples, and the accuracy and reliability were confirmed by liquid chromatography-mass spectrometry (LC-MS/MS). Results showed that the relative standard deviation between the DON strips and LC-MS/MS was <9%. The recovery rates in corn samples ranged from 92 to 104%. The established TRFIA-DON test strip had the characteristics of high sensitivity, high accuracy, and a wide linear range which was suitable for rapid and quantitative determination of DON in food crops and feeds at both on-site and laboratory.

Immunochromatographic assays are good analytical tools for the detection of drug residues. We report a nanosphere-based time-resolved fluorescence immunoassay (nano-TRFIA) based on a monoclonal antibody and a portable TRFIA analyzer for the rapid quantification of chlorpromazine (CPZ) residues in pork. Under optimal conditions, the nano-TRFIA detected CPZ residues within 6 min of sample pretreatment. The results showed good linearity (R2 = 0.991), with a limit of detection (LOD) of 0.32 μg/kg, a wide dynamic range of 0.46–10.0 μg/kg, and coefficients of variation (CVs) of the overall intrabatch and interbatch assays of 7.34% and 7.65%, respectively. The nano-TRFIA was also used to detect CPZ at different spiked concentrations in pork, and the results were confirmed via ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The nano-TRFIA was evaluated for the analysis of six commercial pork samples, and the results agreed well with those obtained via UPLC-MS/MS, without significant differences ( P > 0.05 ). Therefore, the proposed nano-TRFIA is a powerful alternative for the rapid and accurate quantification of CPZ residues in pork to meet the required Chinese maximum residue limits for veterinary drugs in foods.