Molecular "wiring" glucose oxidase in supramolecular architecture.
Supramolecular organized multilayers were constructed by multiwalled carbon nanotubes modified with ferrocene-derivatized poly(allylamine) redox polymer and glucose oxidase by electrostatic self-assembly. From the analysis of voltammetric signals and fluorescence results, a linear increment of the coverage of enzyme per bilayer was estimated, which demonstrated that the multilayer is constructed in a spatially ordered manner. The cyclic voltammograms obtained from the indium tin oxide (ITO) electrodes coated by the (Fc-PAH@CNT/GOx)n multilayers revealed that bioelectrocatalytic response is directly correlated to the number of deposited bilayers; that is, the sensitivity is tunable by controlling the number of bilayers associated with ITO electrodes. The incorporation of redox-polymer-functionalized carbon nanotubes (CNT) into enzyme films resulted in a 6-10-fold increase in the glucose electrocatalytic current; the bimolecular rate constant of FADH2 oxidation (wiring efficiency) was increased up to 12-fold. Impedance spectroscopy data have yielded the electron diffusion coefficient (De) of this nanostructure to be over 10(-8) cm2 s(-1), which is typically higher than those systems without CNT by at least a factor of 10, indicating that electron transport in the new supramolecular architecture was enhanced by communication of the redox active site of enzyme, redox polymer, and CNT.
Deng
Liu
L
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, PR China.
Liu
Ying
Y
Yang
Guocheng
G
Shang
Li
L
Wen
Dan
D
Wang
Fuan
F
Xu
Zhiai
Z
Dong
Shaojun
S
D004566:Electrodes; D005949:Glucose Oxidase / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D036103:Nanotechnology; D055672:Static Electricity
D005949:Glucose Oxidase