Scientists say that they have develop a 'litmus paper' for analyzing odor chemistry. Metalloporphyrins are related to the natural pigments found in red blood and green plants. By watching the color change in the presence of a specific aroma, scientists could determine the aroma's source, or what it smelled like.
Litmus paper changes color to reflect the acidity or alkalinity of a substance.
Suslick and Neal Rakow, another Illinois chemist, described the invention in Thursday's issue of the journal Nature. They then exposed the swatch to a variety of vapors. That gave the researchers quantitative data that could be easily matched up with the chemical composition of the vapors. You get the same pattern. Such a system could be used to monitor levels of insecticides in the environment or to sniff out bacteria causing infections.