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Polycyclic aromatic hydrocarbons (PAHs) are significant environmental and food pollutants that can cause cancer. In this work, a specific monoclonal antibody (mAb) to identify pyrene (PYR) and benzo [a]pyrene (BaP) was prepared, and an indirect competitive enzyme-linked immunoassay (ic-ELISA) was established to detect PYR and BaP residues in living aquatic products for the first time. The effects of complete antigens with different coupling ratios on the production of high-sensitivity mAb was explored. Under the optimal conditions, the IC50 value was 3.73 ± 0.43 µg/L (n = 5). The limits of detection (LODs) for PYR and BaP in fish, shrimp, and crab ranged from 0.43 to 0.98 µg/L. The average recoveries of the spiked samples ranged from 81.5–101.9%, and the coefficient of variation (CV) was less than 11.7%. The validation of the HPLC-FLD method indicated that the ELISA method set up in this experiment provided a trustworthy tool for PAHs residues detection in aquatic products.

Objectives Fluoroquinolones (FQs) are widely used in aquaculture, and their residues have caused many problems threatening human health. Here, this study aims to develop a colloidal gold immunochromatographic strip based on gold-labeled microwells to screen the residues of FQs on site. Materials and Methods The Protein A Magarose Beads affinity chromatography method was adopted to purify the ascites against FQs. By using a strategy of heterologous coating antigen, different coating antigens are applied to detect FQs. The gold-labeled microwell immunochromatographic assay was used to improve the sensitivity of the test strip by the advanced reaction of antigen and antibody. Results The antibodies were verified to be of high purity up to 99%, and the titer reached 1:1,024,000. The combination (enoxacin-OVA and the antibody) detected the 4 banned FQs (pefloxacin, PEF; norfloxacin, NOR; lomefloxacin, LOM; ofloxacin, OFL) with IC50 values ranging from 1.3 to 2.1 ng/mL and cross-reactions ranging from 67.3 to 106.1%. The analysis of spiked crucian carp, silver carp, grass carp, and shrimp samples showed that the limit of detection for PEF, NOR, LOM, and OFL was 4 µg/kg. A comparative study with LC–MS/MS demonstrated that the assay provides an effective screening tool for the rapid detection of FQs residues. Conclusions The results indicated that the test strip can realize full coverage recognition of the 4 banned FQs and has good accuracy, specificity, reproducibility, and stability; therefore, they are more suitable for rapid detection of FQs in aquatic products.

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