Illuminating invisible bloody fingerprints with a fluorescent polymer

Careful criminals usually clean a scene, wiping away visible blood and fingerprints. However, prints made with trace amounts of blood, invisible to the naked eye, could remain. Dyes can detect these hidden prints, but the dyes don't work well on certain surfaces. Now, researchers reporting in ACS Applied Materials & Interfaces have developed a fluorescent polymer that binds to blood in a fingerprint—without damaging any DNA also on the surface—to create high-contrast images.