Biocomposites of covalently linked glucose oxidase on carbon nanotubes for glucose biosensor.
The formation of covalently linked composites of multi-walled carbon nanotubes (MWCNT) and glucose oxidase (GOD) with high-function density for use as a biosensing interface is described. The reaction intermediates and the final product were characterized by using FT-IR spectroscopy, and the MWCNT-coated GOD nanocomposites were examined by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Interestingly, it was found that the GOD-MWCNT composites are highly water soluble. Electrochemical characterization of the GOD-MWCNT composites that were modified on a glassy carbon electrode shows that the covalently linked GOD retains its bioactivity and can specifically catalyze the oxidation of glucose. The oxidation current shows a linear dependence on the glucose concentration in the solution in the range of 0.5-40 mM with a detection limit of 30 microM and a detection sensitivity of 11.3 microA/mMcm2. The present method may provide a way to synthesize MWCNT related composites with other biomolecules and for the construction of enzymatic reaction-based biofuel cells and biosensors.
Li
Jian
J
Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing, 210093, PR China.
Wang
Yue-Bo
YB
Qiu
Jian-Ding
JD
Sun
Da-Cheng
DC
Xia
Xing-Hua
XH
D015374:Biosensing Techniques / Q000295:instrumentation*; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry*; D008956:Models, Chemical; D037742:Nanotubes, Carbon; D013055:Spectrophotometry, Infrared
D037742:Nanotubes, Carbon; D005949:Glucose Oxidase; D005947:Glucose