According to a recent article in FoodProcessing Magazine, Wahroonga, Australia, a team of researchers and development scientists are coming closer to making paper that could warn consumers of contamination. Imagine if food packaging could warn us if a product inside was contaminated with pathogens like E. coli and Salmonella. The concept could soon be a reality, after the team at McMaster University developed a new way to print paper with biosensors.

The result of the research would give consumers a clear, simple answer in the form of letters and symbols that appear on the test paper to indicate the presence of food contamination.

"Imagine being able to clearly identify contaminated meat, vegetables, or fruit. For patients suspected of having infectious diseases like C. difficile, this technology allows doctors to quickly and simply diagnose their illnesses, saving time and expediting what could be life-saving treatments," said John Brennan, director of McMaster’s Biointerfaces Institute, who conducted the research with biochemist Yingfu Li and graduate student Carmen Carrasquilla. "This method can be extended to virtually any compound, be it a small molecule, bacterial cell, or virus," Brennan added.

Current paper-based bio sensing techniques are labor-intensive and often expensive, and can be difficult to mass produce.

Using state-of-the-art methods to produce "bio-inks," researchers can now use conventional office inkjet printers to print man-made DNA molecules with very high molecular weight on paper, much like printing a letter in an office. The sheer size of the DNA—which produces a signal when a specific disease biomarker is present—is enough to ensure it remains immobilized, and therefore stable. The paper sensor emerges from the printer ready to use, much like pH paper.

The implications are significant, says Brennan, since this new technology could be used in many fields where quick answers to important questions are critical. "We could conceivably adapt this for numerous applications, which would include rapid detection of cancer or monitoring toxins in the water supply. There are hundreds of possibilities," he added.