Label detects counterfeiting or tampering

Oxygen-sensing nanoparticles doped into food labels could be used to detect tampering or adulteration according to researchers from Xiamen University and the Fujian Institute Research on the Structure of Matter in China.

Many foods such as meat, potato chips and fruit, are vacuum or modified atmosphere (usually nitrogen or carbon dioxide enriched) packed where oxygen is excluded or reduced. The Chinese researchers have developed a simple and effective way of revealing if the oxygen content of the package has changed. They incorporate honeycomb-like nanospheres made from commercially available polymer into the label. The nanospheres change colour when exposed to oxygen so if the product is tampered with a colour change will be visible in the label.

"To the best of our knowledge, this is the first anti-counterfeit material that undergoes a colour transition stimulated by oxygen content," write the authors of the paper, which is published in the journal Sensors and Actuators B: Chemical (September 2016 edition).

They suggest that their technique for manufacturing the nanoparticles is relatively low cost and environmentally friendly compared to the production of other oxygen-sensing materials.