London, February 29 : UK scientists have invented a device that can facilitate the detection of diseases in the tiniest drop of blood or urine.
Christoph Walti and Giles Davies, the researcher duo at the University of Leeds who led the project, said that their device was 10 times smaller than existing sensors.
The researchers, who insist that their device can detect a range of protein molecules associated with different diseases, used electrodes instead of conventional glass slides to make it.
According to them, the electrodes used were only about 10 micrometers apart, and could ultimately be made even smaller.
For identifying disease proteins with current technologies, scientists have to label proteins with fluorescent tags, and then use optical techniques to spot diseases.
With this process, only one protein can be tested at a times. Besides, such tests are both complex and imprecise.
"We wanted to short-circuit that. So in real time a clinician might be able to take a sample, mush it up and put it over an electrode array and say immediately that a cancer is present and what the origin of that cancer might be," New Scientist magazine quoted Paul Ko Ferrigno as saying.
To serve this purpose the researchers created peptide aptamers, artificial antibodies that are very stable and bind easily to a specific proteins, and attached them to their microscopic electrodes.
According to them, as a target protein binds to an aptamer, the electrodes immediately indicates its presence by generating an electronic signal.
With a view to testing the effectiveness of their device, the researchers exposed an array of electrodes to a mixture made from broken down yeast cells that had similar complexity to blood or urine.
While one set of electrodes carried aptamers with an affinity for a particular protein found in the mixture, the others had nothing attached.
The researchers observed that electrodes with aptamers lit up to signal the presence of the proteins when dipped into the mixture.
They said that the device could be manufactured with the help of technology already commonplace in the microchip industry, and thus it should be simple to increase the number of sensors involved, and to scale the device down further.
"Using semiconductor technology provides huge advantages," says Davies.
In their study report, published in the Journal of Biology, the researchers claimed that their research offered the possibility of a device capable of identifying multiple proteins simultaneously, and even analysing multiple protein interactions at the level of a single cell.