The researchers turned to highly fluorescent, hollow nanotubes that grow dim when they react with compounds given off by meat as it decomposes.

‘When researchers exposed the portable nanotube system to a teaspoon of vapor emitted by meat and fish samples, it reacted in under an hour, fast enough to serve as a real-time measure of freshness. The nanotubes grow dim when they react with compounds given off by meat as it decomposes.’

To test the nanotubes, the team sealed commercial samples - 1 gram each - of pork, beef, chicken, fish and shrimp in containers for up to four days. When they exposed the portable system to a teaspoon of vapor emitted by the samples, it reacted in under an hour, fast enough to serve as a real-time measure of freshness. The researchers also found that if the tubes' glow dulled by more than 10%, this meant a sample was spoiled. 




The study was published in the ACS Sensors.
Source-IANS