Electrochemical biosensing platforms using poly-cyclodextrin and carbon nanotube composite.
Carbon nanotubes (CNTs) were "dissolved" in mixed solution of cyclodextrin (CD) and cyclodextrin prepolymer (pre-CDP) and were used as modifier to fabricate chemical modified electrode. The dispersions of CNTs in different solutions were characterized using UV-vis spectrophotometer. The insoluble conducting composite film of poly-cyclodextrin (CDP) and carbon nanotube was synthesized, and glucose oxidase (GOx) was immobilized on the film to fabricate amperometric biosensor. The CNT-CDP electrode was stable. It can keep the exceptional chemical and physical properties of CNTs and the host-guest chemical reaction ability of cyclodextrins. Cyclic voltammetry measurements of potassium ferricyanide solution (50 mM, and scan rate 100 mVs(-1)) shows that the CDP film was compact and the CNT-CDP film maintains the electrocatalytic activity of CNT. Glucose oxidase was used as a model enzyme to prepare a glucose biosensor. The bioactivity of immobilized glucose oxidase was maintained due to the biocompatibility of cyclodextrin. Amperometric measurements were done with different concentrations of glucose. The CNT-CDP/GCE-GOx biosensor has wide concentration ranges and good sensitivity to glucose. It showed a detection limit of 3.5 μM with a linear range from 0.004 to 3.23 mM and from 4.26 to 10.00 mM. In addition, the biosensor can be operated under wide pH range (pH 5.6-7.8) without great changes in its sensitivity.
Yang
Haipeng
H
College of Materials Science and Engineering, Shenzhen University, and Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060, PR China. yanghp@szu.edu.cn
Zhu
Yongfa
Y
Chen
Dongcheng
D
Li
Chunhui
C
Chen
Shiguo
S
Ge
Zaochuan
Z
D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D003505:Cyclodextrins / Q000737:chemistry*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure
D003505:Cyclodextrins; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D005949:Glucose Oxidase; D005947:Glucose