Hapten design, monoclonal antibody preparation, and immunoassay development for rapid detection of naproxen†

Naproxen (NPX) is a non-steroidal anti-inflammatory drug that poses a significant environmental threat due to widespread use and resistance to degradation. Here, a high-affinity monoclonal antibody (mAb) against NPX was prepared by computer-aided hapten design, mouse immunization, and cell fusion. The conformation of the hapten predicted by computer-assisted molecular simulation was consistent with the mouse immunization results. A highly sensitive immunochromatographic assay (ICA) was established based on this mAb for the detection of NPX in sewage, soil and serum with cut-off values of 0.5 ng mL⁻¹, 2 μg kg⁻¹, and 5 ng mL⁻¹, detection limits of 0.010 ng mL⁻¹, 0.051 μg kg⁻¹, and 0.028 ng mL⁻¹, and recovery rates of 90.3–98.1%, 90.3–106.5%, and 96.9–106.0%, respectively. The detection results of real samples were highly consistent with LC-MS/MS, thereby demonstrating reliability of the proposed ICA.