Chemical staining enhanced Enzyme-linked immunosorbent assay for sensitive determination of Clenbuterol in food

•Some chemical dyes were studied to improve the catalytic activity of HRP.•Chemical staining strategy for enhancing performance of ELISA was firstly proposed.•Sensitivity and detection range of proposed ELISA were enhanced simultaneously. Exploring a novel strategy for strengthening the catalytic activity of enzyme facilitates the development of a sensitive enzyme-linked immunosorbent assay (ELISA). Herein, a chemical staining (CS) strategy was firstly discovered to possess the ability to directly improve the catalytic activity of horseradish peroxidase. Based on this discovery, coomassie brilliant blue was introduced into ELISA to establish a CS enhanced ELISA (CS-ELISA) to detect clenbuterol (CL) by simply staining monoclonal antibodies. Satisfactorily, the most important analytical parameters of CS-ELISA, including sensitivity (0.074 ng mL−1) and linear range (0.2–2 ng mL−1) were all improving 2-folds compared with conventional ELISA. Moreover, the CS-ELISA shows good applicability in the detection of CL in pork tenderloin samples. The proposed CS-ELISA shows various advantages, such as cost-effective, easily accessible, enhanced catalytic activity of enzyme, higher sensitivity, and broader linear range, providing a new insight into enhanced ELISA for food safety.