Nerve gases, the most toxic of chemical warfare agents, are colourless, odourless, and tasteless. As they are called, these gases affect the transmission of nerve impulses through the nervous system.
But researchers at the University of Michigan said the new paper strips they developed are designed in such a way that it could change its colour from blue to pink within 30 second of exposure to trace amounts of nerve gas.
"To detect these agents now, we rely on huge, expensive machines that are hard to carry and hard to operate," Jinsang Kim, an associate professor of materials science & engineering at the university, said in a statement
"We wanted to develop an equipment-free, motion-free, highly sensitive technology that uses just our bare eyes."
The new sensors, which is detailed online in the journal Advanced Functional Materials, combine a group of atoms from a nerve gas antidote with a molecule that changes colour when it's under mechanical stress.
The antidote's functional group binds to the nerve gas, and the resulting stress triggers the colour-changing molecule to turn from blue to pink.
In their experiment, the researchers used a less toxic "nerve agent simulant" related to Sarin gas. Their sensors were able to detect its presence at a concentration of 160 parts per billion, which is five times less than the amount that would kill a monkey.
"We believe these paper strips would detect real and potent nerve gases faster and in even lower concentrations considering their high vapor pressure and more volatile properties," Kim said.
"It feels so gratifying when we, as scientists and engineers, can provide solutions to our society through research."
The university, which is trying to patent the invention, is now seeking commercialisation partners to help bring the technology to market.
The research is funded by the National Science Foundation and the National Research Foundation of Korea.
