A glucose biosensor based on direct electrochemistry of glucose oxidase immobilized on nitrogen-doped carbon nanotubes.
A novel biosensor for glucose was prepared by immobilizing glucose oxidase (GOx) on nitrogen-doped carbon nanotubes (CNx-MWNTs) modified electrode. The CNx-MWNTs membrane showed an excellent electrocatalytic activity toward the reduction of O(2) due to its diatomic side-on adsorption on CNx-MWNTs. The nitrogen doping accelerated the electron transfer from electrode surface to the immobilized GOx, leading to the direct electrochemistry of GOx. The biofunctional surface showed good biocompatibility, excellent electron-conductive network and large surface-to-volume ratio, which were characterized by scanning electron microscopy, contact angle and electrochemical impedance technique. The direct electron transfer of immobilized GOx led to stable amperometric biosensing for glucose with a linear range from 0.02 to 1.02 mM and a detection limit of 0.01 mM (S/N=3). These results indicated that CNx-MWNTs are good candidate material for construction of the third-generation enzyme biosensors based on the direct electrochemistry of immobilized enzymes.
Deng
Shengyuan
S
Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, PR China.
Jian
Guoqiang
G
Lei
Jianping
J
Hu
Zheng
Z
Ju
Huangxian
H
D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D009584:Nitrogen / Q000737:chemistry*
D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D005949:Glucose Oxidase; D005947:Glucose; D009584:Nitrogen