These holograms could test urine, blood, saliva and other substances like alcohol, glucose and hormones. The device uses a material similar to a contact lens, called hydrogel, which is impregnated with silver nano particles. Using a laser pulse, these nano particles form predetermined 3D holographic shapes.
The presence of a particular compound will cause these hydrogels to expand or shrink, changing the color of the hologram. The sensing mechanism can be reset and the same sensor can be used multiple times.
Scientists say the biggest advantage of this technology is its ability to form holograms in a fraction of a second, making it suitable for mass production. They believe the device would be useful in the developing world, where a simple blood glucose test is out of reach for many.
At present the device is being tested to monitor glucose levels and to detect urinary tract infections in diabetic patients. Details about the device have been published in the the journal Advanced Optical Materials.
"While these sorts of inexpensive, portable tests aren't meant to replace a doctor, holograms could enable people to easily monitor their own health, and could be useful for early diagnosis, which is critical for so many conditions," said Ali Yetisen, a PhD student at the University of Cambridge who led the research.
[University of Cambridge]
[Advanced Optical Materials]