An optoelectronic 'nose' for the detection of toxic industrial chemicals has been developed at the University of Illinois.
The sensor array, which is around the size of a postage stamp, uses a series of tiny coloured dots which is digitally imaged with a scanner before and after exposure to an odour-emitting substance.
"Our device is simply a digital multidimensional extension of litmus paper," commented Professor Kenneth Suslick, who led the development team.
"We have a six by six array of different nanoporous pigments whose colors change depending on their chemical environment."
Unlike similar devices that have been developed in the past, the colorimetric sensors are not affected by changes in relative humidity and could serve as a small, wearable sensor that can detect multiple airborne toxins.
Earlier this year it was discovered that an electronic nose developed by NASA could be used to detect odour differences in normal and cancerous brain cells.