New weapon in anthrax identification

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physicists recently joined forces to perfect a powerful new weapon to identify anthrax spores.

‘Our procedure can work for monitoring anthrax in mail, but it can also scan the whole atmosphere. And there are a lot of other potential applications -- monitoring glucose in the blood, for example,’ said Marlan Scully, Distinguished Professor of Physics at Texas A&M and holder of a joint faculty appointment at Princeton’s Applied Physics and Materials Science Group.

The new technique is based on coherent anti-Stokes Raman scattering (CARS), a phenomenon that measures the light scattering that occurs when a molecule is bombarded by photons. When a molecule is hit by an appropriate sequence of laser pulses, it gives off light in a specific ‘fingerprint’ pattern. If three laser pulses are used, the resultant emitted light yields a coherent signature at a particular frequency.

‘Unfortunately, however, when anthrax molecules are subjected to such study, their CARS signature can be obscured by background signals from other molecules present in the medium containing the anthrax spores,’ Scully explained.