Gun Cartridges Coated in Pollen-based Nanotags Could Help ID Criminals A superteam of British scientists and researchers are working on a nanotechnology that, when applied to gun cartridges, act as microscopic tags that place themselves on and around everything they come in contact with, such as criminals. The bullet tags are part natural pollen, part nanoparticles that are extremely difficult to wash off and can also keep skin cells stuck to the gun cartridges. The technology is said to be heat-resistant, cost effective and could be in use within a year. [PhysOrg via Pop Sci ]