Today.Az » Weird / Interesting » Pocket chemistry: DNA helps glucose meters measure more than sugar
25 July 2011 [19:20] - Today.Az
Glucose meters aren't just for diabetics anymore. Thanks to University of Illinois chemists, they can be used as simple, portable, inexpensive meters for a number of target molecules in blood, serum, water or food.
Chemistry professor Yi Lu and postdoctoral researcher Yu Xiang published their findings in the journal Nature Chemistry.
"The advantages of our method are high portability, low cost, wide
availability and quantitative detection of a broad range of targets in
medical diagnostics and environmental monitoring," Lu said. "Anyone
could use it for a wide range of detections at home and in the field for
targets they may care about, such as vital metabolites for a healthy
living, contaminants in their drinking water or food, or potential
disease markers."
A glucose meter is one of the few widely available devices that can
quantitatively detect target molecules in a solution, a necessity for
diagnosis and detection, but only responds to one chemical: glucose. To
use them to detect another target, the researchers coupled them with a
class of molecular sensors called functional DNA sensors.
Functional DNA sensors use short segments of DNA that bind to
specific targets. A number of functional DNAs and RNAs are available to
recognize a wide variety of targets.
They have been used in the laboratory in conjunction with complex and
more expensive equipment, but Lu and Xiang saw the potential for
partnering them with pocket glucose meters.
The DNA segments, immobilized on magnetic particles, are bound to the
enzyme invertase, which can catalyze conversion of sucrose (table
sugar) to glucose. The user adds a sample of blood, serum or water to
the functional DNA sensor to test for drugs, disease markers,
contaminants or other molecules. When the target molecule binds to the
DNA, invertase is released into the solution. After removing the
magnetic particle by a magnet, the glucose level of the sample rises in
proportion to the amount of invertase released, so the user then can
employ a glucose meter to quantify the target molecule in the original
sample.
"Our method significantly expands the range of targets the glucose
monitor can detect," said Lu, who also is affiliated with the Beckman
Institute for Advanced Science and Technology and with the Frederick
Seitz Materials Research Lab at U. of I. "It is simple enough for
someone to use at home, without the high costs and long waiting period
of going to the clinics or sending samples to professional labs."
The researchers demonstrated using functional DNA with glucose meters
to detect cocaine, the disease marker interferon, adenosine and
uranium. The two-step method could be used to detect any kind of
molecule that a functional DNA or RNA can bind.
Next, the researchers plan to further simplify their method, which
now requires users to first apply the sample to the functional DNA
sensor and then to the glucose meter.
"We are working on integrating the procedures into one step to make
it even simpler," Lu said. "Our technology is new and, given time, it
will be developed into an even more user-friendly format."
The U.S. Department of Energy, the National Institutes of Health and the National Science Foundation supported this work. /Science Daily/
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