creating knowledge for future

High Quality

Scholarly Publishing
                CAREER NETWORK  
World's one of the largest Research
Career Network
  •     Academic & Industry jobs
  •     Project funding
  •     Visiting faculty positions
  •     Visiting scientist positions
  •     Invited talks
  •     and more...  
Register FREE  
  Chemical Sensors 2013, 3: 1
  Research Article
Dithizone as a halochromic material for fabricating evanescent wave-based chemical sensors
  Justus C. Ndukaifea,d, A. G. Agwu Nnannaa,b, Harold W. Pinnickc  
a Purdue Water Institute, Purdue University Calumet Hammond IN, 46323, USA
b Department of Mechanical Engineering, Purdue University Calumet Hammond IN, 46323, USA
c Department of Chemistry and Physics, Purdue University Calumet Hammond IN, 46323, USA
d Department of Electrical and Computer Engineering Purdue University West-Lafayette IN, 47907, USA

  This paper presents for the first time the use of dithizone as a pH sensitive material in the fabrication of an optical fiber evanescent wave-based sensor for ammonia detection. A thin film of dithizone was immobilized on the decladded section of an optic fiber and the sensing region was encapsulated in protective gas permeable Poly-di-methyl-siloxane (PDMS) layer. The sensor was calibrated for ammonia detection in water ranging from 42 ppm to 434 ppm, and exhibited excellent reversibility (over 99%). Experimental results also showed that the sensor can serve the dual purpose of detecting ammonia (a base), and acidic gases, while discriminating one from the other.
  Halochromism; Evanescent wave; Optical fiber; Ammonia; Dithizone; Bathochromic shift  

  © 2016 Cognizure