Smelling and Tasting Electronically

The human nose and tongue are excellent quality-control sensors. For example, we can tell whether food is spoiled by its disagreeable odor and taste. Because it s impractical to use humans as sensors in industrial settings, several companies are now developing electronic noses. 

Another type of electronic nose was developed at Lund University in Sweden specifically to detect the odors associated with spoiled fish. In this case the sensor uses two enzymes linked to a polymer to detect the presence of amines such as histamine, putrescine, and cadaverine. Such amines are produced by microbes as fish spoil. 

A company called Alpha M.O.S. has recently introduced what it calls the world s first commercial electronic tongue, a device used to identify various tastes associated with liquids. Like the Cyranose the electronic tongue must first be 

Humans and animals are still the best smellers and tasters, but computers are rapidly catching up.  

The N03 ion is known to be planar with 120-degree bond angles  

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