S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Chemical and Biological Engineering (화학생물공학부) Journal Papers (저널논문_화학생물공학부)
Field-Effect-Transistor Sensor Based on Enzyme-Functionalized Polypyrrole Nanotubes for Glucose Detection
- Yoon, Hyeonseok; Ko, Sungrok; Jang, Jyongsik
- Issue Date
- American Chemical Society
- J. Phys. Chem. B, 2008, 112, 9992-9997
- We describe the detection of glucose based on a liquid-ion gated field-effect transistor configuration in which
enzyme-functionalized polypyrrole nanotubes are employed as the conductive channel. First of all, carboxylated
polypyrrole nanotubes (CPNTs) were successfully fabricated by the chemical polymerization of an intrinsically
functionalized monomer (pyrrole-3-carboxylic acid, P3CA) without degradation in major physical properties.
The CPNTs possessed not only well-defined functional groups but also electrical properties comparable to
nonsubstituted polypyrrole. Importantly, the carboxylic acid functional group can be utilized for various
chemical and biological functionalizations. A liquid-ion gated FET sensor was readily constructed on the
basis of the chemical functionality of CPNTs. In the first stage, the CPNTs were immobilized onto a
microelectrode substrate via covalent linkages. It was noteworthy that the covalent immobilization allowed
high-quality contact between the nanotubes and the microelectrodes in the liquid phase. The second stage
involved the covalent binding of glucose oxidase (GOx) enzyme to the nanotubes. The covalent functionalization
generally provides excellent enzymatic activity and thermal stability. The fabricated FET sensor provided
real-time response (an increase in source-drain current) and high sensitivity toward the various concentrations
(0.5-20 mM) of glucose. The enzymatic reaction product, hydrogen peroxide, played pivotal roles in
modulating the charge transport property of CPNTs.
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