A recent Shuttle experiment could yield biosensors that harness living cells to detect harmful chemicals or biotoxins. Microbes encapsulated in biosensors by a nanoscale self-assembly method were genetically engineered to glow fluoresecent green when sensing specific toxins. After exposure to radiation and the cold vacuum of space, the biosensor prototype will return to Earth from the International Space Station on the next Shuttle flight for additional testing. If the biosensor continues to function, Sandia National Laboratories said it will develop rugged sensor technology that could be used for battlefield reconnaissance. Sandia earlier reported that it could direct the self-assembly of nanocyrstals into thin films. By controlling nanocystal structure so they self-organize to encapsulate the living cells, the researchers were able to seal them in a controlled environment that for use as biosensors. If the cells survive aboard the space station and continue functioning as biosensors when returned to Earth, then the reseachers expect to develop biosensor applications. For instance, the Defense Department is looking for a tiny biosensor carried by insects onto the battlefield. Unmanned aircraft could remotely detect any fluoresecent green generated by biological weapons or other biohazards.