Chemical and biological ring sensor
A first-of-its kind ring sensor can detect chemical and biological threats. American Chemical Society

Researchers have designed a sensor that can be worn as a ring and can detect the presence of a wide array of harmful chemical and biological substances, including explosives and highly toxic nerve agents.

In a breakthrough against terrorism, Joseph Wang and his colleagues from the University of California say the wearable device shows considerable promise for meeting the demands of a wide range of defence and security scenarios.

"With increasing terrorist threats and political instability, there are urgent needs for developing wearable sensing platforms for detecting chemical and biological threats," the researchers said.

In future, the ring-based sensor could also be modified for use in other areas, for example, in industries which deal with hazardous chemicals.

The first-of-its kind device is made up of two parts: an electrochemical sensor cap for detecting chemical and biological threats, and a circuit board which processes and alerts a smartphone or laptop when a hazardous substance is identified.

To test the prototype, the team exposed the ring to explosives and organophosphate nerve agents – which prevent the nervous system from working properly - finding that it was highly sensitive to both targets and was also very selective – minimizing the possibility of false alarms.

The study detailing the detection device is published in the American Chemical Society journal ACS Sensors.

Wearable sensors are revolutionizing the world of tech because of their ability to carry out a huge range of useful functions, from monitoring people's heart rate to tracking elderly people with dementia. Some are even becoming fashionable with many sporting sleek, stylish designs.

According to global analyst firm CCS Insight, the wearable electronics market will be worth $34 billion by 2020. Among the wearable sensors currently in development are devices which will be implemented inside wristbands, mouth guards, headbands and even tattoos.

Earlier this year, Wang also developed another device for detecting dangerous chemicals which was reported in the same journal. The disposable "lab-on-a-glove" can detect the presence of organophosphate pesticides on food produce which can be harmful to humans if ingested.