A team of chemists from the University of Montreal have developed a DNA-based electrochemical diagnostic test that is inexpensive and can provide results in just a few minutes. This development has the potential to lead to point-of-care medical devices that can provide results for diagnoses ranging from cancer to autoimmune diseases in just minutes.
Not only is this development exciting for the advancement of the scientific community, it also has the potential to impact global health due to the low cost and ease of use of the test. The new development could help cut lag time and expenses between diagnosis and treatment for both communicable and non-communicable diseases on a global level.
Molecular Diagnostics at Home
“Despite the power of current diagnostic tests, a significant limitation is that they still require complex laboratory procedures. Patients typically must wait for days or even weeks to receive the results of their blood tests,” Alex Vallée-Bélisle said, head of the research team.
At the core of the DNA-based device is one of the simplest forces in chemistry: steric effects. Essentially, the new development focuses on the phenomenon of atoms getting too close to one another and using force to push off each other. This reaction allows researchers to detect a wide array of protein markers.
An Accidental Discovery
And much like some of the greatest scientific discoveries, the development of this novel diagnostic test came purely by chance.
“While working on the first generation of these DNA-base tests, we realised that proteins, despite their small size (typically 1000 times smaller than a human hair) are big enough to run into each other and create steric effect (or traffic) at the surface of a sensor, which drastically reduced the signal of our tests,” said Sahar Mashid, postdoctoral scholar at the University of Montreal and first author of the study. “Instead of having to fight this basic repulsion effect, we instead decided to embrace this force and build a novel signaling mechanism, which detects steric effects when a protein marker binds to the DNA test.”
This from the University of Montreal:
The sensing principle is straightforward: the diagnostically relevant protein (green or red), if present, binds to an electro-active DNA strand, and limits the ability of this DNA to hybridize to its complementary strand located on the surface of a gold electrode.
Because the sensing principal can be generalized to many targets, the new test has the ability to detect dozens of disease markers in less than five minutes.
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