Researchers from Rensselaer Polytechnic Institute have discovered that graphene foam can outperform leading commercial gas sensors in detecting potentially dangerous and explosive chemicals. The foam is made from several graphene sheets (grown on Nickel, which was later removed) and is flexible, rugged and retains graphene's important properties.
The new sensor successfully and repeatedly measured ammonia (NH3) and nitrogen dioxide (NO2) at concentrations as small as 20 parts-per-million. The graphene foam sensor is about the size of a postage stamp and the thickness of felt. Here's a video discussing the production method of the graphene foam: