You typically won't know you're infected with E. coli until it starts wreaking havoc on your gut. That's why a group of scientists from Washington State University are building a handheld biosensor that can sniff out even tiny amounts of pathogen in food. The biosensor will rely on flower-shaped nanoparticles the team developed. These nanoflowers can trap bacteria enzymes and amplify them, so they can be recognized by a simple pH strip. According to team leader Yuehe Lin, they plan to use the nanoflowers to create a simple biosensor similar to a pregnancy test strip that anyone can use.