Dual-strategy enhanced lateral flow immunoassay based on matrix tolerant antibody and bright aggregation-induced emission label for the sensitive detection of sildenafil

The sensitivity of lateral flow immunoassays (LFIAs) is largely determined by the choice of antibody and labeling material. In this study, monoclonal antibodies (mAbs) against sildenafil were developed, and mAb-3C11 was selected for LFIA development based on its sensitivity and matrix tolerance. Additionally, aggregation-induced emission fluorescent microspheres (AIEFMs) were synthesized as the signal label. Combining the high performance antibody with the outstanding label, the LFIA@AIEFMs showed good sensitivity, with a limit of detection of 0.15 ng mL −1 , which is 4.4 times lower than that of LFIA using commercially available dyed latex microspheres. LFIA@AIEFMs was successfully applied to sildenafil detection, yielding recovery rates between 78.8 % and 130.4 % (coefficient of variation <15 %). Results were consistent with LC-MS analysis, confirming the robustness and practical applicability of the developed LFIA.