The US Army has awarded a contract to Platypus Technologies for the development of a portable sensor that can detect deadly gases and other toxins.

Under the $2.2m contract, Platypus will continue to develop sensors that have an ultra-thin layer of gold film coated with receptors that make it turn lighter or darker when it comes in contact with a targeted substance.

The sensor will use tiny liquid crystals, which are used in LCD television and computer screens, for the changes in the color intensity.

Platypus president and chief executive Richard S Schifreen said the company also developed a prototype of a handheld device for reading the sensors and refining the technology for certain applications, including military uses.

Work under the one-year contract will be carried out by Platypus in collaboration with Edgewood Chemical and Biological Center in Maryland.