Holograms could detect E. coli or salmonella, making food safer

The translucent membranes, dubbed “edible optics” by their creators at Massachusetts’ Tufts University, have been studded with tiny grooves and crests to create the kind of light-diffracting holograms more often associated with credit cards and passports. Unlike your Visa or MasterCard, however, you can eat silk with no ill effects, suggesting a future in which pure fibers fashioned into films or membranes are embedded with biological sensors and incorporated into produce bags to warn of E. coli or salmonella contaminants.