Sentinel wrap – a new invention to test the freshness of food

According to the World Health Organization (WHO), food-borne pathogens cause about 600 million diseases and 420,000 deaths per year. About 30% of these cases affect children under the age of five and younger.


Researchers at McMaster University(Canada) have developed a test to check that meat and other food products are safe to eat . The research team worked together to develop a transparent test patch that could signal food contamination . The patch can be introduced directly into the packaging, thereby monitoring the content of harmful pathogens such as E. coli and Salmonella.

Sentinel wrap

The new technology described in the ACS Nano research journal has the potential to replace the traditional term ” best before ” on food and beverages. The mechanism of the test is simple – if the pathogen is present in the food or drink inside the package, a signal will be generated that could be read by a smartphone or other simple mobile device . The test itself has no effect on the contents of the food package.

Scientists call the new material ” Sentinel Wrap” as a tribute to an interdisciplinary research network based on the McMaster Sentinel Bioactive Paper Network . The food freshness test technology was developed in the McMaster University laboratories.


Mass production of such a transparent patch would be quite cheap and simple, as the researchers say. As a result, any food producer could easily integrate the test into the production process. According to the researchers, the introduction of the test on the market would require a commercial partner and the approval of regulatory authorities. They emphasize that the same technology can be used differently, e.g. in the case of bandages, to indicate whether the wounds have been infected or to wrap surgical instruments to ensure their sterility.


Source: Hanie Yousefi, M. Monsur Ali, Hsuan-Ming Su, Carlos DM Filipe, Tohid F. Didar. Sentinel Wraps: Real-Time Monitoring of Food Contamination by Printing. DNAzyme Probes on Food Packaging. ACS Nano, 2018;

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