Diabetes Test detects glucose

Researchers from the U.S. have invented a new biosensor that could eventually eliminate or reduce the frequency of using pinpricks for diabetes testing. The sensor is able to detect minute concentrations of glucose in saliva, tears and urine in contrast to conventional diabetes tests that measure glucose in blood.

The sensor consists of several layers of nanosheets resembling rose petals that are made of graphene, which is a one-atom-thick film of carbon. The edges of the petals have dangling, incomplete chemical bonds to which platinum nanoparticles and enzyme glucose oxidase can attach. The enzyme then converts glucose to peroxide, which generates a signal on the electrode of the sensor.

The technology is able to detect glucose in concentrations as low as 0.3 ?M, which is far more sensitive than other available devices. It is able to distinguish between glucose and signals from other compounds in the blood, such as uric acid, ascorbic acid and acetaminophen, that often cause interference in sensors.

“What’s unique is that we can sense in all four different human serums: the saliva, blood, tears and urine,” said Johnathan Claussen, a former Purdue University doctoral student and researcher at the U.S. Naval Research Laboratory. With this wide linear sensing range, the sensor thus opens possibilities for new inherently noninvasive ways to monitor glucose content in the body, he added.

Furthermore, the researchers say that the biosensor can be manufactured at low costs. The production of conventional nanostructured sensors involves lithography, chemical processing, etching and other steps. The petals, however, can be grown on almost any surface, according to Anurag Kumar, a doctoral student at Purdue University who led the project in collaboration with Claussen. “It could be ideal for commercialization,” he said.

In addition, the technology could also be used for sensing of other chemical compounds to test for further medical conditions. “Because we used the enzyme glucose oxidase in this work, it’s geared for diabetes but we could just swap out that enzyme with glutamate oxidase, for example, in order to measure the neurotransmitter glutamate to test for Parkinson’s and Alzheimer’s,” Claussen said.

Original Source: The Dental Tribune.com