An international team of scientists has developed a prototype biosensor that can identify traces of chemical residues left over in soil and water in a matter of minutes. A commercial version of the sensor could help identify sites contaminated with potentially dangerous herbicides. Researchers from the US, the Czech Republic and Italy worked together on the reusable prototype. The new biosensor uses a protein complex from a type of cyanobacterium - bacteria that fix carbon dioxide in the presence of light and can grow at very high temperatures.