Nanotech microchip to diagnose type-1 diabetes

Researchers have developed an inexpensive, portable, microchip-based test to diagnose type-1 diabetes.
Scientists at the Stanford University School of Medicine developed the test which employs nanotechnology to detect type-1 diabetes outside hospital settings.
The handheld microchips distinguish between the two main forms of diabetes mellitus, which are both characterised by high blood-sugar levels but have different causes and treatments.
Until now, making the distinction has required a slow, expensive test available only in sophisticated health-care settings.
"With the new test, not only do we anticipate being able to diagnose diabetes more efficiently and more broadly, we will also understand diabetes better - both the natural history and how new therapies impact the body," said Brian Feldman, assistant professor of pediatric endocrinology and the Bechtel Endowed Faculty Scholar in Pediatric Translational Medicine.

Type-1 diabetes is an autoimmune disease in which patients' bodies stop making insulin, a hormone that plays a key role in processing sugar.

The disease begins when a person's own antibodies attack insulin-producing cells in the pancreas. The auto-antibodies are present in people with type-1 but not those with type-2, which is how tests distinguish between them.
The old, slow test detected the auto-antibodies using radioactive materials, took several days, could only be performed by highly-trained lab staff and cost several hundred dollars per patient.
In contrast, the microchip uses no radioactivity, produces results in minutes, and requires minimal training to use. Each chip, expected to cost about USD 20 to produce, can be used for upward of 15 tests.

The microchip also uses a much smaller volume of blood than the older test; instead of requiring a lab-based blood draw, it can be done with blood from a finger prick.
The microchip relies on a fluorescence-based method for detecting the antibodies.
The team's innovation is that the glass plates forming the base of each microchip are coated with an array of nanoparticle-sized islands of gold, which intensify the fluorescent signal, enabling reliable antibody detection.
In addition to new diabetics, people who are at risk of developing type-1 diabetes, such patients' close relatives, also may benefit from the test because it will allow doctors to quickly and cheaply track their auto-antibody levels before they show symptoms.

The researchers have filed for a patent on the microchip, and are seeking the US Food and Drug Administration approval of the device.
The study was published in the journal Nature Medicine.