Ferrocenecarboxaldehyde (FcCHO) was covalently bound onto the multi-wall carbon nanotubes functionalized with amino groups (AMWNTs) to achieve Fc-AMWNTs conjugate. The cyclic voltammetry were used to characterize the nanocomposites. Here, Fc-AMWNTs were applied to construct glucose biosensors with IO4--oxidized glucose oxidase (IO4--oxidized GOx) through the covalent assembly method without any cross-linker. The presence of both ferrocene as mediator of electron transfer and MWNTs as conductor enhanced greatly the electrocatalytic response toward the glucose. Furthermore, our enzyme electrodes also showed remarkable stability due to the covalent interaction between the Fc-AMWNTs and the GOx.