基于离子液体功能化石墨烯/碳纳米管的葡萄糖传感器的研究

Preparation and properties of a glucose biosensor electrode based on an ionic liquid-functionalized graphene/carbon nanotube composite

将离子液体功能化的石墨烯/碳纳米管(G-IL/CNTs)修饰到玻碳电极上,再固载上葡萄糖氧化酶(GOD)和辣根过氧化物酶(HRP),构筑了新型的(G-IL/CNTs)/(GOD+HRP)/GC双酶葡萄糖传感器。用SEM观察电极形貌,发现碳纳米管类似于导线穿插在石墨烯片层中,连接了各石墨烯片层,两者结合形成了三维立体结构,明显提高了石墨烯的分散性,同时由于功能化后的石墨烯与碳纳米管的协同作用,该传感器在葡萄糖的检测上表现了良好的分析性能,传感器的线性范围为0.004~5 mmol/L,灵敏度为53.89μA mmol/L^-1cm^-2,检出限为3.99×10^-7mol/L(S/N=3)。

A novel glucose biosensor electrode was fabricated by loading a glassy carbon electrode with a 1-methyl imidazolebased ionic liquid-functionalized graphene/carbon nanotube(CNTs)composite,which was used to immobilize horseradish peroxidase(HRP)and glucose oxidase(GOD)for glucose detection.SEM,AFM and FTIR were used to investigate the micro structures and morphology of the electrode.The electrochemical performance of the electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy.Results indicate that the electrode has an excellent electrocatalytic activity towards glucose.A biosensor prepared at the optimal loading amount of the composite and HRP/GOD ratio has a linear range of 0.004-5 mM,a detection limit of 3.99×10^-7 M and a sensitivity of 53.89μA mM^-1 cm^-2 for glucose detection with an excellent stability and reproducibility.The excellent performance of the biosensor is ascribed to the stable three-dimensional structure of the composite,where graphene sheets provide a large surface area for immobilizing the two enzymes and CNTs inserted between the graphene sheets to decrease electron transfer resistance.