The Biosensor works by incorporating antibodies to the specific chemical (drug, hormone, viral protein or pesticide, for example) that it has been designed to detect.

ECONOMIST: Medical diagnostics

Nano bar codes are the molecular versions of traditional bar codes--metal nano-particles that have specific, recognizable chemical fingerprints that can be read by a machine, perhaps a UV lamp or optical microscope.

FORBES: Safer And Guilt-Free Nano Foods

This would permit the detection of chemical signatures associated with specific atmospheric gases and perhaps even some surface processes.

BBC: Kepler telescope spies 'most Earth-like' worlds to date

They focused on measuring the density of a specific type of receptor that responds to the mood chemical serotonin.

BBC: NEWS | Health | Hope for early Alzheimer's test

Like chemical skeleton keys, these generic compounds can quickly be customized to gum up specific kinases as their roles in disease become clearer.

FORBES: Machine Gunner

President Barack Obama said the US had seen evidence of chemical weapons being used in Syria - but it was important to get more specific information about what happened.

BBC: Syria conflict: BBC shown 'signs of chemical attack'