Smelling in color: a rainbow of possibilities

A sensor that detects dangerous odors better than the human nose may be able to "smell" dangerous air pollutants, soil contaminants, insecticides, food pathogens, biological warfare neurotoxins, and body odors associated with illness and disease. Called "smell-seeing" by its inventors, the method relies on color changes that occur in an array of vapor-sensitive dyes in response to exposure. By measuring the color change pattern, the researchers can identify a contaminant both qualitatively and quantitatively. This newest version of an artificial nose is simple, fast, and inexpensive. It can also eliminate the subjectivity associated with the human sense of smell and the perception of odors.