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Bandages That Change Color When a Wound Gets Infected

You won’t yet find it on pharmacy shelves, but German researchers have developed a dye with potentially promising applications in wound treatment. It operates on a principle not much different from litmus paper: It turns purple when pH level around it is between 6.5 and 8.5, which turns out to be a useful way to detect infection, as it presents a deviation from the typical pH value for skin of 5 or below.


The scientists at the Fraunhofer Research Institution for Modular Solid State Technologies EMFT in Munich have developed an indicator dye that reacts to different pH values, and integrated it into a dressing and a plaster. Healthy skin and healed wounds usually show a pH value of or below 5. If this value increases, shifting from the acid into the alkaline range, it indicates complications in the healing of the wound.

“If the pH value is between 6.5 and 8.5 an infection is frequently present and the indicator color strip turns purple, “ says Dr. Sabine Trupp, a scientist at the EMFT. In this way the intelligent dressing material makes it possible to regularly check wounds from the outside without disrupting the healing process.

Next steps: Testing the bandages out in a hospital setting, mass-producing the dye, and perhaps even integrating the bandage with optical sensors which could provide precise pH readouts, allowing medical professionals to precisely track the progress of an infection’s healing.

(Gizmag via DVICE)

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