Bioresource-derived tannic acid-supported immuno-network in lateral flow immunoassay for sensitive clenbuterol monitoring

Although lateral flow immunoassay (LFIA) as a point-of-care (POC) diagnostic tool has been widely used because of numerous merits, it remains challenging to realize higher sensitivity, easier labeling, and fewer antibodies consumption. Herein, a bioresource-derived tannic acid (TA)-supported immuno-network based LFIA for clenbuterol (CLE) monitoring was proposed by employing poly TA nanospheres (PTAN) as the new tracer. Attributing to the effective protein-enrichment ability of TA, plenty of goat anti-mouse immunoglobulins (GAMI) were first absorbed on the surface of PTAN and then monoclonal antibodies (Ab CLE ) were added to form immuno-network. Compared with directly coupling antibodies, the utilization efficiency of Ab CLE was significantly improved. Thus, the detection sensitivity (take the cut-off value as an example) was enhanced 5-fold and 10-fold at least compared with PTAN-Ab CLE and colloidal gold-based LFIA, respectively. Additionally, the proposed method was successfully verified in beef and pork liver and provided an effective strategy for food safety monitoring.