A new type of biosensor based on yeast, jellyfish proteins, and a rat's sense of smell could sniff out explosives, landmines, and agents, such as sarin gas, according to researchers at Temple University. Writing in the June issue of Nature Chemical Biology, Danny Dhanasekaran and colleagues describe how they have used genetic engineering to modify a strain of yeast with proteins responsible for the rat's sense of smell and linked it to another protein that glows green when stimulated. When the olfactory machinery in the engineered yeast cells "smell" the odor of dinitrotoluene, a compound closely related to trinitrotoluene, for instance, they stimulate the fluorescent green protein, producing an almost instant alarm.

"We suspected that harnessing the potential of the olfactory system, which can detect innumerable chemical agents with unparalleled sensitivity and selectivity, would be of immense value in the detection of environmental toxins and chemical warfare agents even at sub-lethal levels," explains Dhanasekaran. The team is now fine-tuning the sensor to make it work faster, as well as developing an alternative version for medical therapeutic applications and to aid the drug discovery process.

Dhanasekaran believes his natural approach to sensors could soon see them incorporated into handheld devices or remote sensing stations for monitoring sensitive sites.

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Nature Chem Biol, 2007, in press; http://dx.doi.org/10.1038/nchembio882

http://temple.edu/biochemistry_medical/Dr.DDhanshek.html

http://www.chemspider.com/RecordView.aspx?id=8150