Now Smartphones to Detect Toxic Gases

Researchers have developed a new low cost sensing material that can be integrated in electronic circuits and can enable smartphones to detect toxic gases within seconds.

Researchers from National Institute for Materials Science in Japan and Massachusetts Institute of Technology (MIT) developed the chemical sensing material whose electrical conductivity dramatically increases when exposed to toxic gases.

Scientists developed a low-cost chemical sensing material consisting of a group of carbon nanotubes (CNTs) individually wrapped with supramolecular polymers – clusters of monomers held together through weak interactions.

The material’s electrical conductivity increases up to 3,000 times when it is exposed to electrophilic toxic gases.

CNTs alone are highly conductive materials, but when they are wrapped with supramolecular polymers, which serve as insulators, they become poor conductors.

The supramolecular polymers were designed so that weakly bound sites in the molecules are dissociated when these sites are exposed to toxic gases, causing the wrapping molecules to disassemble. As a result, the original high conductive state of CNTs is restored.