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Oklahoma State University has claimed a breakthrough in the detection of
organophosphate nerve gases (WO 00/45149). Today’s test equipment is so bulky
that people could start dying before it has been lugged into place. The new test
gear can be worn like a badge and gives an immediate readout. A laser inside the
badge shines on a film of porphyrin molecules—similar to parts of
chlorophyll and haemoglobin molecules. OPs cause a change in electron
configuration, which in turn leads to a shift of one or two nanometres in the
wavelength of light reflected from the porphyrin. The wavelength of the
reflected light is checked against a library of signatures.