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Sticker detector will detect dangerous bacteria in meat
Natalia Pelezneva, Naked Science
Researchers from McMaster University in Canada have developed a transparent sensory "patch" capable of detecting dangerous bacteria in meat products. Upon contact with pathogenic E. coli, the material begins to glow. The authors of the project believe that over time, such detectors will be able to replace the expiration date markings on packages. An article about the development was published in the journal ACS Nano (Yousefi et al., Sentinel Wraps: Real-Time Monitoring of Food Contamination by Printing DNAzyme Samples on Food Packaging).
The base of the sticker is made of transparent and flexible cycloolefin polymer (COP). Deoxyribozymes, DNA molecules with catalytic activity and capable of splitting other molecules, including RNA molecules, were applied to a thin layer of polymer. To create a prototype, deoxyribosime RFD-EC1 was used, which reacts only in the presence of E. coli. On the sticker there is a slightly luminous substrate, whose glow is suppressed by a quencher protein. When E. coli appears, RFD-EC1 is activated and destroys the connection with the "extinguisher" – the sticker begins to fluoresce.
The scheme of Sentinel Wrap / © ACS Nano
According to the researchers, such sensors have never been applied to a flexible polymer surface before. To make the prototype, the engineers used inkjet printing: microscopic drops of the substance were sprayed onto the prepared substrate. The resulting sensor remains effective for at least two weeks. At the same time, the composition of the sticker does not react with the usable product.
The developers of the sticker detectors say that the technology allows you to create sensors that are sensitive to other pathogenic bacteria, including salmonella. Such stickers can be placed on packages of various products and beverages. The production of sensors is relatively inexpensive, so in the future they can be used instead of labeling with an expiration date. This method is more reliable, because the product sometimes begins to deteriorate before the expiration date – for example, if it is stored incorrectly.
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