二茂铁功能化Fe_3O_4/碳纳米管/壳聚糖复合膜葡萄糖生物传感电极的研究

Design and Development of A Novel Glucose Biosensor Based on the Ferrocene-Functionalized Fe_3O_4 Nanoparticles/Carbon Nanotubes/Chitosan Nanocomposite Film Modified Electrode

采用交联法制备了羧基二茂铁功能化Fe3O4纳米粒子（FMC．AFNPs）复合材料，并将该复合纳米材料与多壁碳纳米管（MWNTs）、壳聚糖（CS）及葡萄糖氧化酶（GOD）混合修饰于自制的磁性玻碳基底0WGC）表面。制备了GOD／FMC-AFNPs／MWNTs／CS复合膜生物传感器电极．实验结果表明，FMC．AFNPs复合材料有效地克服了二茂铁在电极表面的泄漏，且FMC．AFNPs／MWNTs／CS复合膜良好的生物兼容性较大地改善了固定化GOD的生物活性．MWNTs具有良好的导电性和大比表面积，在修饰膜内可作为电子传递“导线”，极大地促进电极的电子传递速率，提高电极的电催化活性和灵敏度．该电极的葡萄糖检测的线性范围为1．0x10^-5～6．0x10^-3mol·L^-1，检测限为3．2×10^-6mmol·L^-1（S／N=3），表观米氏常数为5．03·10^-3mmol·L^-1，且有较好的稳定性和重现性．

A novel platform for the fabrication of glucose biosensor was successfully constructed by entrapping glucose oxidase （GOD） in a ferrocene monocarboxylic acid-aminated Fe304 magnetic nanoparticles conjugate （FMC-AFNPs）/chitosan （CS） /multiwall carbon nanotubes （MWNTs） nanocomposite. The formation of FMC-AFNPs could effectively prevent the leakage of ferrocene and retain its electrochemical activity. This GOD/FMC-AFNPs/CS/MWNTs matrix provided a biocompatible microenvironment for retaining the native activity of the immobilized GOD. Moreover, the presence of MWNTs enhanced the charge-transport properties of the composite and facilitated electron transfer between the GOD and the electrode for the electrocatalysis of glucose. Under the optimal conditions the designed biosensor to glucose exhibited a wide and useful linear range app of 1.0xl0-5 to 6.0x10^-3 mol.L^-1 with a low detection limit of 3.2x10^-6 mol.L^-1（S/N=3）. The value of KM was 5.03x10^-3 mol·L^-1, indicating that the biosensor possesses higher biological affinity to glucose. Furthermore, the biosensor possesses satisfactory stability and good reproducibility.