Sensor sniffs out spoiled fish.

Does something smell fishy? A new sensor developed by scientists at Lund University in Sweden can provide a chemically accurate answer to that question by acting as a simple electronic nose (SN: 2/19/2000, p. 125).

As fish spoil, microbes break down amino acids and produce compounds such as histamine, putrescine, and cadaverine. If ingested, these substances can disturb the heart, other muscles, nerves, and stomach. The new sensor uses two enzymes, crosslinked with a polymer, that detect the presence of the amine compounds. The researchers' study appeared on March 4 in the online version of ANALYTICAL CHEMISTRY.

If fish are left at room temperature for 3 days, the histamine concentration rises to a toxic level, according to the team's analysis. At 4 [degrees] C, however, the concentration of amines remains the same even after 10 days.