Researchers Built a ‘Nose’ to Find Rotting Food and Dead People

We’ve all opened our fridge at some point, only to be hit with the smell of death. But a team of Korean researchers have created a bioelectronic “nose” that could one day detect rotting food before it goes supernova in your crisper. Plus, it could help find dead bodies.

In a study published last week in ACS Nano, researchers detailed how they created their “nose.” Rotting proteins produce a compound called cadaverine, which gives the smell of rotting meat its putrid punch. (Any crime-show watcher will recognize the root word “cadaver,” or corpse.) When people or protein-rich foods start to decompose, they excrete ever-increasing amounts of cadaverine. So the researchers looked to an animal known for its ability to smell even traces of cadaverine: the zebrafish.

Proteins from a zebrafish’s olfactory system, known as receptors, eagerly grab onto cadaverine molecules. To copy zebrafish receptors, researchers used the protein-producing powerhouses E Coli. bacterium as hosts. Then, the proteins were arranged into membrane-like structures called nanodiscs. This was done to mimic how the proteins would be positioned in an actual cell. The nanodiscs were assembled into a carbon nanotube field-effect transistor, and the nose was ready for sniffing.

Researchers used liquefied foods such as salmon and pork fat to test the nose, and found that it was sensitive to even low levels of rot. Similar “noses” may be useful for food safety purposes or for developing new preservatives. But the research might also be put to a more gruesome use. Right after disasters such as earthquakes or floods, it could come in handy for first responders to detect where bodies are hidden. But for the rest of us, it may simply save us from performing the dreaded “sniff test” on that salmon pasta we really should have thrown out last week.

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