A dual signal amplification immunosensor based on glucose oxidase (GOD)-functionalized nanocomposites was developed for the detection of clenbuterol. The characteristics of the nanocomposites were confirmed by scanning electron microscopy (SEM) and spectrophotometry. The results indicate that GOD in the nanocomposites keeps good enzyme dynamic response and electro-catalysis performance. The detection mechanism of the immunosensor was investigated by electrochemical methods of differential pulse voltammetry (DPV). A set of experimental conditions were also optimized for the detection of clenbuterol. The developed immunosensor exhibited high sensitivity, selectivity and reproducibility, which had a wide linear range of 0.01～100 ng/mL and a low detection limit of 4.50 pg/mL for clenbuterol. Accurate detection of clenbuterol in pig liver samples was demonstrated by standard addition method.

Key words: glucose oxidase, immunosensor, clenbuterol, β-agonist