Turkeys\' color-changing skin inspires smartphone toxin sensor

U.S. researchers said they've turned to the animal world, particularly to turkeys, for inspiration for a smartphone system to detect toxins. A new type of biosensor that changes color when exposed to chemical vapors mimics the skin on a turkey's head, which can turn from red to blue to white thanks to bundles of collagen that are interspersed with a dense array of blood vessels, scientists at the University of California, Berkeley, reported Tuesday. Spacing between the collagen fibers changes when the blood vessels swell or contract, depending upon whether the bird is excited or angry, which affects how the light is scattered and alters the colors. Berkeley researchers studied this color-changing ability to create biosensors that can detect volatile chemicals. "In our lab, we study how light is generated and changes in nature, and then we use what we learn to engineer novel devices," bioengineering Professor Seung-Wuk Lee said. The researchers have created a mobile app, called the i-Color Analyzer, demonstrating that a smartphone photo of the sensor's color bands could be used to help identify toxins of interest. "Our system is convenient, and it is cheap to make," Lee said. "We also showed that this technology can be adapted so that smartphones can help analyze the color fingerprint of the target chemical."