With chronic wounds, nursing staff has to change the dressing regularly – not just for reasons of hygiene, but also to examine the wound, take swabs and clean it. Not only does this irritate the skin unnecessarily but bacteria can also get in.
The researchers believe it would be much better to leave the bandage on for longer and have the nursing staff ‘read’ the condition of the wound from outside.
As part of the fluorescence sensing integrated into medical textiles (Flusitex) project, a bandage was designed with sensors incorporated into the base material which glow with a different intensity if the wound’s pH level changes.
This would mean a gentler treatment for patients, less work for the nursing staff and, therefore, lower costs.
The portable, cheap and easy-to-use device for measuring can monitor several parameters at once, including fluorescence, pH, glucose and oxygen levels. Thanks to a colour scale, the quantity of the emitted substance be deduced.
To create the fluorescent sensor biomarker, the research team designed a molecule composed of benzalkonium chloride and pyranine.
“This biomarker works really well,” said Empa chemist Guido Panzarasa, “especially at pH levels between 5.5 and 7.5. The colours can be visualised with simple UV lamps available in electronics stores.”
Benzalkonium chloride also has an antimicrobial effect.
According to the researchers, it might one day be possible to read the signals with the aid of a smartphone camera.