chemists at the massachusetts institute of technology mit have come up with a portable sensor that can detect gases emitted by rotting meat, mit has said.it says that this will allow customers to determine whether the meat in the supermarket or fridge is safe to eat.the sensor consists of chemically modified carbon nanotubes and that it could be deployed in &lsquosmart packaging&rsquo that would offer much more accurate safety information than the expiration date on the package, timothy swager, professor of chemistry at mit says.&ldquopeople are constantly throwing things out that probably aren&rsquot bad,&rdquo he said and believes it could also cut down on food waste he told the journal angewandte chemie.previously swager&rsquos lab has developed a device that detects the ripeness of fruit. the carbon nanotubes can be chemically modified so that their ability to carry an electric current changes in the presence of a particular gas, mit says.for this study, the researchers tested the sensor on four types of meat pork, chicken, cod, and salmon. they found that when refrigerated, all four types stayed fresh over four days. left unrefrigerated, the samples all decayed, but at varying rates, mit says. mit says that there are other sensors that can detect the signs of decaying meat, but they are usually large and expensive instruments that require expertise to operate.&ldquothe advantage we have is these are the cheapest, smallest, easiesttomanufacture sensors,&rdquo swager says.mit says that the sensor is relatively inexpensive. robert foloni, a science fellow at sealed air the food packaging supplier, said that there are several potential advantages in having the inexpensive sensor.forloni said that such advantages are the freshness of meat and fish products, including preventing foodborne illness, increasing overall customer satisfaction, and reducing food waste at grocery stores and in consumers&rsquo homes.mit says that the new device also requires very little power and could be incorporated into a wireless platform swager&rsquos lab recently developed that allows a regular smartphone to read output from carbon nanotube sensors such as this one.the researchers have filed for a patent on the technology and hope to license it for commercial development, mit says. 
