Ushio has made a great detector that can detect toxins, drugs and many other agents using a new method of detection that was published earlier in 2011.
The technology is interesting. The detection reagent is a Variable region fragment ofHeavy chain antibody (VH) that has the quenched fluorescence group embedded in its structure. This is attached to a Variable region fragment of Light chain antibody (VL) but there is no interaction. Binding of the antigen brings the fragments together and releases the quenched fluorescent molecule thus increasing the fluorescence.
Typically antigen, antibody reactions used to take substantial time since it required development of an enzyme based reagent and several mixing steps but this technique enables the specific detection of an antigen with really fast kinetics. Using their mobile technology they have also enabled the detection onsite using specific reagents in 90 seconds. More details and pictures are on the Japanese website.