CHAMPAIGN, Ill. Imagine a polka-dotted postage stamp that can sniff out poisonous gases or deadly toxins simply by changing colors.
As reported in the Sept. 13 issue of the journal Nature Chemistry, Kenneth Suslick and his team at the University of Illinois have developed an artificial nose for the general detection of toxic industrial chemicals (TICs) that is simple, fast and inexpensive and works by visualizing odors. This sensor array could be useful in detecting high exposures to chemicals that pose serious health risks in the workplace or through accidental exposure.
"Our device is simply a digital multidimensional extension of litmus paper. We have a six by six array of different nanoporous pigments whose colors change depending on their chemical environment," said Suslick, the Schmidt Professor of Chemistry at the U. of I. "The pattern of the color change is a unique molecular fingerprint for any toxic gas and also tells us its concentration. By comparing that pattern to a library of color fingerprints, we can identify and quantify the TICs in a matter of seconds."
To create the sensor array, the researchers print a series of tiny colored dots each a different pigment on an inert backing such as paper, plastic or glass. The array is then digitally imaged with an ordinary flatbed scanner or an inexpensive electronic camera before and after exposure to an odor-producing substance. And, unlike other electronic-nose technologies that have been tried in the past, these colorimetric sensors are not affected by changes in relative humidity.
While physicists have radiation badges to protect them in the workplace, chemists and workers who handle chemicals have no good equivalent to monitor their exposure to potentially toxic chemicals.
This project, which was funded by the National Institute of Environmental Health Sciences at the National Institutes of Health, exemplifies the types of sensors that a
|Contact: Ken Suslick|
University of Illinois at Urbana-Champaign