Researchers have been looking for new ways to improve the safety of our homes. One possible approach has been to genetically engineer plants to make them able to act as “detectors” of sorts. These would be relatively cheap to make, given that they simply grow, and would be far easier to maintain than traditional radon and mold detectors.

Right now, though, teams are a bit far off. A team published a new paper detailing past efforts to accomplish similar goals. Like when scientists modified to tobacco plants to produce a fluorescent orange protein when exposed to disease-causing bacteria.

To pull this off, researchers have been looking for specific chemical markers that are predictors of something else. For instance, the standard smoke detector works by allowing a tiny bit of radioactive material to decay, sending energized particles to another detector. If there’s smoke, the particles won’t make it and the message gets blocked.

In much the same way, scientists are looking at volatile organic compounds. These are an extremely broad category of chemicals, but they are also relatively specific. For an accurate test, you can reduce the scope of the search to a just a few compounds, then isolate the genetic sequences that control for the plant’s response to them. And that’s precisely what the team did — dialing up the reactivity of the plants. Then, with special glasses, researchers were able to see the fluorescent light and effectively test the presence of bacteria.

The potential is pretty vast and could allow for us to screen all kinds of domestic pollutants. They could be built into air vents into what the scientists dubbed “living walls” that could screen for practically anything. And this technology likely wouldn’t take long. Though, for now, the plants would be limited to pigments that glow under UV. Someday researchers hope to find a protein that will be visible to the naked eye, but that’s a ways off.