One of the most confounding aspects of Alzheimer's Disease is our inability to diagnose the condition with certainty until after death. Now, researchers at Lancaster University (LU) in England are claiming a breakthrough in identifying the disease, even in its early stages, using a sensor embedded with a diamond. The hope is that using the device for early detection will improve the quality and length of life for those afflicted by the disease.

In what the university is calling "the largest and most conclusive study of its kind," LU researchers built a sensor with a diamond core measuring about 2-ft (0.6 m) square, which was attached to a computer. They then analyzed about 550 blood plasma samples from healthy individuals as well as those diagnosed with Alzheimer's and other neurodegenerative diseases. Infrared light was passed first through the diamond and then through the sample while the researchers took note of the "fingerprint spectrum" that was produced.

LU professor Francis Martin, principal investigator of the study, explained to New Atlas that by observing the way in which light is absorbed in the sample, the diamond-based analysis could distinguish between various chemical bonds such as those indicative of lipids, proteins, DNA, glycogen, and more.

"The diamond is one variant of the sensing device," Martin told us when we asked why that particular material was used. "The biological sample is placed in close proximity to one surface; the light passes through this surface in a phenomenon known as the evanescent wave – how the chemical bonds in the sample interact with and attenuate this evanescent wave give rise to the fingerprint spectrum."

In the study, the researchers were not only able to identify Alzheimer's disease in the blood samples, but they were also able to sift the data with a fine enough comb to distinguish between the disease and other forms of cognitive impairment.

"A particularly exciting aspect of the study was the ability to distinguish accurately between Alzheimer's disease and Lewy body dementia, which are conditions that both result in dementia and can be difficult to separate from each other based on clinical information and symptoms," said Professor David Mann from the University of Manchester, a long-time collaborator of Martin's. "By reduction of misdiagnosed cases and administration of appropriate treatment, many people could benefit from this type of blood test in the future."

Currently, diagnosing Alzheimer's disease relies on a lengthy series of interviews, observations, scans, and blood and urine tests, and by the time the condition is confirmed, it has often progressed too far for interventional therapies to be completely effective. Martin says that this new blood testing device will be able to diagnose the condition even at the very earliest stages, helping people better manage the symptoms.

"We have an aging population, meaning that the incidence and prevalence of Alzheimer's is increasing, as is the need for accurate diagnosis," he said in a statement. "The ability to identify different neurodegenerative diseases through the analysis of blood offers a faster and accurate way of establishing the most effective treatment plan as well as disease monitoring."

Martin says that he and his team aren't yet working on commercializing the device, which they envision eventually being shrunk down to hand-held size. He does indicate, however, that there are other organizations pursuing that goal across the globe, such as a blood test developed in 2014 that searches for a combination of 10 proteins that are a hallmark of the disease.

However, the LU team does have more work planned. Martin indicated that the method will undergo further validation studies along with diagnostic tests including MRI scans. His team will also attempt to learn more about how to distinguish between spectral biomarkers, and how the test results foreshadow the progress of full-blown neurodegenerative diseases.

The study detailing the work has been published in the Proceedings of the National Academy of Sciences USA.