Consequently, the step size is increased, slightly reducing the accuracy. The thicknesses of the layers are chosen to cause zenith path delays nearly equivalent to those from a standard refractivity atmosphere (see Equation 2 and [12]). The b
Glucose oxidase (GOx) electrodes have been extensively studied as a foundation for constructing biosensors, biomedical devices, enzymatic bioreactors and biofuel cells [1-6]. The most critical challenge in these applications is to immobilize the GOx so that it retains its enzymatic activity and permits fast and efficient electron transfer from the catalytic center to the electrode [7-10]. In order to achieve this, suitable electrode materials such as nanomaterials and special techniques for immobilizing enzymes on the electrode surface have been developed.

Carbon nanotubes were first introduced by Iijima in 1991 [11] and they have come to be regarded as being a very attractive nanomaterial for a wide range of applications [5-6, 12]. Many experiments have been carried out to exploit the unique properties of SWCNTs that can lead to the preservation of catalytic activity and to the achievement of direct electron transfer with the redox active center of the adsorbed oxidoreductase in SWCNT-modified electrodes [5, 13-14]. It had been found that GOx complex and FAD coenzymes can spontaneously adsorb onto annealed carbon nanotubes with an armchair chirality to improve their bioelectrochemical performance respectively while these complexes are cast onto glassy carbon electrodes (GCEs) [5, 13-14].

Moreover, in a cyclic voltammogram experiment, the peak current of intact GOx on a SWCNT-modified GCE was found to be almost 10 times greater than that on an unmodified GCE, but still less than that of the electroactive FAD directly on SWCNT-modified GCE [13]. At one time, Wohlfahrt et al. reported that Glu412 bound to His559 was capable of modulating powerfully its catalytic activity by affecting all the rate constants in the reductive and the oxidative half-reaction of the catalytic cycle while those amino acid residues of apo-GOx along with FAD are in the active site of enzyme [29]. From these cases, it can be apparent that the conformation of FAD in apo-GOx could determine the activity of intact enzyme by influencing on the active structure of redox site.

Consequently, in order to recognize what are about the change of activity with GOx complex adsorbed on SWCNTs, it would be worthy of exploring the conformational mobility mechanism of FAD coenzyme while GOx complex GSK-3 is non-covalently adsorbed on SWCNTs with multiple orientations. Of cause, those experiments on SWCNT-modified electrodes have proven to be an essential experimental base for gaining a fundamental understanding of biological redox reactions and for evaluating potential denaturation mechanisms due to the interaction with SWCNTs [13-14].