While there are already electronic devices that detect toxic gases, they can be expensive, and require training to properly use. Soon, though, there could be a cheap and simple alternative – threads ...

Sensing threads prepared with bromothymol blue (top thread), methyl red (middle thread) and MnTPP (bottom thread) are exposed to ammonia at 0 ppm (left panel) 50 ppm (middle panel) and 1000 ppm (right ...