Oxygen Plasma Functionalized Multiwalled Carbon Nanotube Thin Film as A pH Sensing Membrane of Extended-Gate Field-Effect Transistor

Author

Wan-Lin Tsai ; Bai-Tao Huang ; Po-Yu Yang ; Kuang-Yu Wang ; Ching Hsiao ; Huang-Chung Cheng

Author_Institution

Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

Volume

34

Issue

10

fYear

2013

fDate

Oct. 2013

Firstpage

1307

Lastpage

1309

Abstract

High-performance pH sening membranes of extended-gate field-effect transistors (EGFETs) composed only of oxygen-plasma-functionalized carbon nanotube thin films (CNTFs) are demonstrated. A large number of oxygen-containing functional groups are decorated on the sidewalls of carbon nanotubes (CNTs) after the oxygen plasma treatment. These functional groups act as the sensing sites and accurately respond to the ions of interest in different pH levels. Therefore, these functionalized CNTFs as the pH-EGFET sensing membranes can achieve a high voltage sensitivity of 56.8 mV/pH, a large voltage linearity of 0.9995, and a wide sensing range of pH 1-13. In addition, the oxygen-plasma-functionalized CNTFs also exhibit superior reliability with a small hysteresis voltage of 4.98 mV.

Keywords

carbon nanotubes; ion sensitive field effect transistors; thin film transistors; CNTF; EGFET; ISFET; extended-gate field-effect transistors; functional groups; ion-sensitive field-effect transistors; oxygen plasma treatment; oxygen-plasma-functionalized carbon nanotube thin films; pH sensing membrane; sensing sites; voltage 4.98 mV; voltage linearity; voltage sensitivity; Carbon nanotubes; Hysteresis; Plasmas; Sensitivity; Sensors; Surface treatment; Transistors; Carbon nanotube thin film (CNTF); extended-gate field-effect transistor (EGFET); sensor;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2013.2278214

Filename

6595050