Chip (IMAGE) U.S. National Science Foundation Caption Brian Cunningham of the University of Illinois at Urbana-Champaign is creating a smartphone-based system to detect and track infectious diseases. The system will detect the presence of specific pathogen DNA sequences with the help of photonic crystals, like the one pictured above. The photonic crystals will be used to enhance the output of fluorescence-based assays. The brilliant colors that are observed reflecting from the photonic crystal are caused by resonant reflection from a periodically modulated nanostructure with features smaller than the visible wavelengths. Credit Greg Pluta, University of Illinois at Urbana-Champaign Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.