In part, it is an old idea: biosensors in which chemical reactions are used to report on concentrations of glucose in the blood date back to the 1960s, although only recently has their use for monitoring diabetes been cheap, portable and widespread. Chemical sensing could have countless applications—to detect contaminants in food and water at very low concentrations, for instance, or to monitor pollutants and trace gases present in the atmosphere. Faster, cheaper, more sensitive and more ubiquitous chemical sensing would yield progress in all of those areas.
It is in biomedicine, though, that new kinds of chemical sensors would have the most dramatic potential. For instance, some of the products of cancer genes circulate in the bloodstream long before the condition becomes apparent to regular clinical tests. Detecting these chemicals early might make prognoses more timely and accurate. Rapid genomic profiling would enable drug regimens to be tailored to individual patients, thereby reducing risks of side effects and allowing some medicines to be used that today are hampered by their dangers to a genetic minority.
Some chemists foresee continuous, unobtrusive monitoring of all manner of biochemical markers of health and disease, perhaps providing real-time information to surgeons during operations or to automated systems for delivering remedial drug treatments. This futuristic vision depends on developing chemical methods for selectively sensing particular substances and signaling about them even when the targets occur in only very low concentrations.
SOURCE : SCIENTIFIC AMERICAN MAGAZINE OCTOBER 2011