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 ...

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 ...