WASHINGTON -- Researchers said they have created a sophisticated sensor small and portable enough to be worn like a badge that could monitor the environment for harmful chemicals, allowing people to protect against exposure to toxic substances and spoiled foods, Reuters reported on Friday.

The liquid crystal sensor, about the size of a small band-aid, could provide real-time detection of airborne chemicals that until now have been difficult to detect using technology that still is mostly confined to the laboratory, according to research in the journal ***Science***.

In the future, these sensors could be used in food safety applications, such as monitoring levels of the compounds produced by rotting fish and meat, the researchers said. The sensors also could be used to detect environmental exposure to pesticides, and could possibly certain deadly nerve gases such as sarin.

Technology to detect such compounds already exists, but primarily is confined to the laboratory and is too bulky and complex to provide real-time, portable detection.

University of Wisconsin researcher Nicholas Abbott, who coauthored the study, said the sensor, if used in a broad range of applications, could turn the technology into a multibillion-dollar product.

The sensor "has the potential to be formatted as a broad technology with quite a diverse number of applications from the miliary, to health care, to food safety and occupational safety," Abbott said in an interview.

"The strength of the technology is that it is something that can be realized as a patch or a badge, some low-profile object that could be confined to a person," he said.

Abbott added that early uses of the sensor could be available within between two to three years. Researchers say they will continue to study the technology and develop other applications including a flexible version that could be weaved into clothing.