Electrochemical xanthine biosensor based on carbon nanofiber and ferrocene carboxylic acid for the assessment of fish freshness
摘要
Herein, an electrochemical biosensor based on carbon nanofibers (CNF) and ferrocene carboxylic acid (FcA) modified glassy carbon electrode (GCE) was fabricated for xanthine determination. Xanthine oxidase (XO) was further immobilized onto the FcA/CNF/GCE for the fabrication of the biosensor. The morphologic appearance of the XO/FcA/CNF/GCE was studied by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements were also performed to determine the electrochemical characteristics of the modified electrode. The XO/FcA/CNF/GCE biosensor exhibited linear response for xanthine in the concentration range of 6.0 × 10–7 to 2.0 × 10–4 M with a sensitivity of 6.04 µAmM−1 and a detection limit of 1.7 × 10–7 M. The xanthine biosensor also exhibited the advantages of high reproducibility, anti-interference ability and good long-term stability. Furthermore, the XO/FcA/CNF/GCE was used for the determination of xanthine in fish meat and the satisfactory results indicated that the FcA/CNF matrix is a promising candidate for electrode modification.