University of Illinois chemists coupled functional DNA sensors and glucose meters for fast, easy, portable detection of drugs, toxins, disease markers, and other molecules in blood, water, or food. Image: Li Huey Tan, Yu Xiang and Yi Lu |
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 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 says. “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,” says 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 says. “Our technology is new and, given time, it will be
developed into an even more user-friendly format.”
Study abstract: Using Personal Glucose Meters and Functional DNA Sensors to Quantify a Variety of Analytical Targets
