Chinese scientists create gas detector as sensitive as dog's sniffer

WASHINGTON - A team of Chinese scientists has used graphene to create an artificial gas detector that is as good as a dog's nose.

The study, reported Wednesday in ACS Nano, a monthly scientific journal of the American Chemical Society, showed that the graphene-based nanoscrolls can mimic a dog's sensitive sniffer, which is lined with millions of tiny capillaries.

It is well known that dogs have a better sense of smell than humans. For years, scientists have been trying to develop an artificial detector that is just as good as a canine's nose.

Drawing inspiration from the capillary structure, researchers from South China Normal University and Beihang University found a way to modify the graphene with a polymer to make high-quality nanoscrolls.

These nanoscrolls have a large surface area like that in dog's nose. They are stable at high temperatures, and are strong and durable.

Previous studies have produced the graphene-based nanoscrolls, which are nanosheets of graphene rolled up in continuous and uniform manner.

But they are difficult to manufacture, consume a lot of energy and difficult to scale up.

And past studies have used raw graphene or modified graphene that either left behind some unrolled structures, or shriveled up and aggregated, respectively.

The team prepared graphene-based nanoscrolls with the addition of poly or sodium-p-stryrenesulfonate, using the freeze-drying method to create uniform, unaggregated structures.

It showed that the nanoscrolls had a wide, tubular shape, and almost all of the graphene was rolled up.

The researchers then incorporated the nanoscrolls into a gas sensor, which was highly selective and sensitive.

They said that this method had the potential for large-scale production.