Electrochemical immunosensing using a nanostructured functional platform for determination of α-zearalanol

We describe an electrochemical immunosensor for the determination of the growth promoter alpha-zearalanol in bovine serum. The sensing scheme is based on a nanocomposite consisting of gold nanoparticles electrodeposited on multi-walled carbon nanotubes that were modified with poly (vinylpyridine) through in-situ polymerization. The electrodeposition of the gold nanoparticles enlarges the surface available for immobilization of antibodies against alpha-zearalanol. The nanocomposite film was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and cyclic voltammetry. The calibration plot has a linear response in the concentrations range from 0.05 to 50 ng mL(-1), and the detection limit is 16 pg mL(-1). The time required for analysis is 12 min only which compares quite favorably with the time (90 min) required by the conventional ELISA. The method exhibits good selectivity, stability and reproducibility for detecting alpha-zearalanol in the livestock production.