基于石墨烯-辣根过氧化物酶修饰电极的过氧化氢传感器

本文采用Hurnmers方法制备了氧化石墨，通过超声波振荡后得到氧化石墨烯并用水合肼进行还原，制得还原石墨烯，结果表明，制备的氧化石墨烯材料的层间距由原料石墨的0.33 nm增加到0.86 nm，结构上出现了含氧基团，还原后的石墨烯某些含氧基团消失。制备了基于石墨烯修饰辣根过氧化物酶（HRP）电极的过氧化氢传感器，该传感器以石墨烯（GR）作为酶的载体，壳聚糖（CS）为粘结剂，硫堇（Th）作为电子传递材料，玻碳电极（GC）为基体，结果显示，石墨烯和硫堇在修饰电极中有协同作用的效果，基于GR-Th-HRP-CS/GC修饰电极的过氧化氢传感器，具有良好的检测性能，催化电流与H2O2浓度的线性范围为5.0×10-5~1.1×10-3 mol/L，检测限为9.53×10-7 mol/L，表观米氏常数 为6.55×10-5 mol/L，该传感器具有优越的过氧化氢检测性能，可用于过氧化氢含量检测。

Hydrogen Peroxide Biosensor Based on Graphene Modified Horseradish Peroxidase Electrode

Graphite oxide was prepared by Hummers method. Graphene oxide was obtained from ultrasonic oscillation of graphite oxide and then reduced by using hydrazine hydrate to get graphene (GR). The results showed that the prepared graphene oxide enlarged interlamellar spaces compared to graphite which was from 0.33 nm to about 0.86 nm. The structure of graphene oxide contained many oxygen groups which resulted in the increase of interlamellar space and hydrophilism. After reducion, some oxygen groups disappeared. Hydrogen peroxide biosensor based on graphene modified horseradish peroxidase electrode was prepared by using graphene as enzyme carrier, chitosan (CS) as binder, thionine (Th) as electrical mediator and glass carbon (GC) as electrode matrix. Graphene and Th had the synergistic effect on HRP-GR-Th- CS/GC electrode. The cyclic voltammetric experiment results demonstrated that the current response of the biosensor was linear to hydrogen peroxide content ranging from 5.0×10-5 to 1.1×10-3 mol/L, with detection limit of 1.50×10-6 mol/L and apparent Michaelis-Menten constant ( ) of 6.55×10-5 mol/L. The biosensor has good detection performance especially for hydrogen peroxide thus can be used for detecting hydrogen peroxide content.