Yeast Colony Patches Act Like Living Geiger Counters
Most people don’t think twice about the radiation when they check in for a routine X-ray. But for radiologists and workers at nuclear power plants, the risk is persistent.
To save them from side effects, workers use protective clothing and patches, called dosimeters, that keep track of radiation exposure and warn the wearer if they have reached dangerous levels. The only problem is, these patches are worn for a month or two before being shipped off for analysis. It can take another week after that before the results come in.
A faster way to measure exposure may soon be on its way, thanks to a team of researchers from Purdue University who have designed a dosimeter that can measure radiation exposure in near real time. It’s simple, made out of little more than paper and yeast, and costs pennies on the dollar. A paper detailing the device was published recently in the journal Advanced Biosystems.
The patch works by enveloping a yeast colony (the same kind used to brew beer and make bread) within freezer paper, aluminum, and tape. After being worn for a day or so, wearers place a drop of water on the patch and scan it with a system that measures how much yeast remains by how well the patch conducts electricity. Radiation kills yeast so, the less yeast, the higher the wearer’s radiation exposure.
“We put the yeast inside an electrical device, a capacitor, and when activated with water the electrical characteristic of the device changes,” Babak Ziaie, an electrical and computer engineer at Purdue and co-author of the paper, told Digital Trends. “When radiation goes through some of the yeast, it damages the yeast, so we can electrically detect radiation by detecting the response of the yeast to radiation.”
The patch’s biggest advantage is in its near real-time readout, which can help both radiologists and responses to nuclear disasters, who are exposed to much higher levels of radiation and may not have the luxury to wait weeks for results.
The patch can detect radiation doses down to one milliard, according to the researchers, which puts it close to par with conventional dosimeters. The researchers hold a patent to the device but have not yet decided on how the move forward with it commercially. Either way, it will still take several years for the device to go through regulatory approval before it comes to market.