Lou Gehrig’s disease, a progressive neurodegenerative disease also known as amyotrophic lateral sclerosis (ALS), is estimated to affect more than 20,000 Americans, according to the ALS Association.
The disease is hard to diagnose as there isn’t one definitive test or procedure used for diagnosis, which is often made by ruling out other diseases. But that could change, thanks to new research from the University of Illinois at Chicago.
Using graphene and cerebrospinal fluid, researchers were able to accurately detect whether a patient had ALS, multiple sclerosis or no neurodegenerative disease.
Graphene is a single-atom thick material composed of carbon atoms arranged in a hexagonal lattice. Each carbon atom is bound to its neighbor via chemical bonds. The elasticity of these bonds produce resonant vibrations, also known as phonons, which can be accurately measured. When a molecule interacts with graphene, it changes resonant vibrations in a very specific and quantifiable way.
“Graphene is just one atom thick, so a molecule on its surface in comparison is enormous and can produce a specific change in graphene’s phonon energy, which we can measure,” said Vikas Berry, associate professor and head of chemical engineering in the UIC College of Engineering and an author of the study, in a statement.
Berry and his colleagues obtained cerebrospinal fluid from the Human Brain and Spinal Fluid Resource Center and tested the cerebrospinal fluid from 13 people with ALS, three with multiple sclerosis, three with an unknown neurodegenerative disease and seven people who did not have a neurodegenerative disease.
“We saw unique and distinct changes in graphene’s phonon energies depending on whether the fluid was from someone with ALS, multiple sclerosis or someone without neurodegenerative disease,” Berry said. “We were also able to determine whether the fluid was from someone over age 55 or younger than 55 when we tested cerebrospinal fluid from ALS patients. We think the difference we see between older and younger ALS patients is driven by unique biochemical signatures we are picking up that correlate to inherited ALS, which usually produces symptoms before age 55, and what’s known as sporadic ALS which occurs later in life.”
Berry believes the graphene is detecting unique biosignatures – or combinations of proteins and other biomolecules – found in the cerebrospinal fluid of people with different diseases.
“The electronic properties of graphene have been extensively studied, but only recently have we begun to examine its phononic properties as a way to detect diseases,” said Berry. “And it turns out that graphene is an extremely versatile and accurate detector of biosignatures of diseases found both in cerebrospinal fluids and whole cells.”
Other authors on the paper include UIC’s Dr. Ankit Mehta, Bijentimala Keisham, Steven Denyer, Pouyan Kheirkhan, Gregory Arnone and Abhiraj Bhimani, as well as Akop Seksenyan from the Rosalind Franklin University of Medicine and Science and Clive Svendsen from Cedars-Sinai Medical Center.
The research was funded by a UIC seed grant, as well grants from the Office of Naval Research and the National Science Foundation.