▎ 摘　　要

A novel nonenzymatic voltammetric Xanthine biosensor was constructed based on a three-dimensional porous nanocomposite of reduced graphene oxide/polypyrrole/CdO nanocomposite modified glassy carbon electrode (GCE/rGO/PPy/CdO) for measuring of Xanthine. The structure and morphology of rGO/PPy/CdO nanocomposites were characterized by field emission scanning microscopy, Raman spectroscopy, X-ray diffraction, UV-vis spectroscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. The GCE/rGO/PPy/CdO based biosensor exhibited excellent electrocatalytic activity and high stability for Xanthine oxidation. Under optimized conditions, the linearity between the current response and the Xanthine concentration was obtained in the range of 1-800 mu M with a detection limit of 0.11M (S/N=3). The biosensor was used to determine the Xanthine in fish meat with satisfactory results.