Affiliation:
1. Department of Electrical and Computer Engineering, California State University, Fresno, CA 93740, USA
Abstract
In this project we investigated the extended-gate field-effect transistor (EGFET) structure used with ITO (Indium Tin Oxide)/PET (Polyethylene Terephthalate) sensitive films acting as the extended-gate part of an EGFET obtained from a combination of FETs from the CD4007 chip. We tested the device as a pH sensor by immersing the ITO/PET electrode in several chemical solutions of acidic and basic nature, including hydrogen peroxide, acetic acid, sulfuric acid, and ammonium hydroxide, at different concentrations. Using a Tektronix 4200A sourcemeter, we plotted the current–voltage (I–V) characteristics for the different chemical solutions, and we established a correlation to the pH changes. Results from the plotted I–V characteristics show a great dependance of the drain current (ID) on solution concentration. Furthermore, we measured the pH of each of the used solutions, and we established a relationship between the drain current and the pH value. Our results show a consistent decrease in the current with an increase in the pH value, although with different rates depending on the solution. The device showed high voltage sensitivity at 0.23 V per pH unit when tested in sulfuric acid.
Subject
Electrical and Electronic Engineering,Biochemistry,Instrumentation,Atomic and Molecular Physics, and Optics,Analytical Chemistry
Reference20 articles.
1. Development of an Ion-Sensitive Solid-State Device for Neurophysiological Measurements;Bergveld;IEEE Trans. Biomed. Eng.,1970
2. Twenty Years of Ion-selective Field-effect Transistors;Janata;Analyst,1994
3. Thirty years of ISFETOLOGY: What happened in the past 30 years and what may happen in the next 30 years;Bergveld;Sens. Actuators B Chem.,2003
4. Bergveld, P. (2003, January 20–22). ISFET, theory and practice. Proceedings of the IEEE Sensor Conference Toronto, Toronto, ON, Canada.
5. Lilienfeld, J.E. (1930). Method and Apparatus for Controlling Electric Currents. (US1745175A), US Patent.
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