Graphene May be Used to Detect Biomarkers for ALS, Study Reports

Graphene, a material made up of a thin sheet of carbon, may be used in the future to detect and measure biomarkers able to identify patients with amyotrophic lateral sclerosis (ALS), according to data from a recent study.

The study, “Quantum Capacitance Based Amplified Graphene Phononics for Studying Neurodegenerative Diseases,” was published in Applied Materials & Interfaces.

ALS is a progressive neurological disorder. Motor neurons — the nerve cells responsible for controlling voluntary muscles — gradually degenerate and die, causing muscles to shrink, or atrophy, and become weaker. Most patients end up dying from respiratory failure 3-5 years after experiencing their first symptoms.

At least 30 genes have been proposed to play a role in ALS; however, the specific causes of disease onset are still not fully understood. This, together with the lack of reliable laboratory tests to identify ALS, contribute to poor disease diagnosis, which affects patients’ treatment and disease progression.

Now, a team of researchers from the University of Illinois at Chicago may have found a way to facilitate ALS diagnosis by using a thin sheet of a material called graphene. This material produces constant vibrations, also known as phonons, whose characteristics change once other materials are placed on its surface. By measuring these changes, researchers are able to tell the differences in the composition of different materials.

“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,” Vikas Berry, associate professor and head of chemical engineering in the UIC College of Engineering and an author of the paper, said in a news release.

In their study, Berry and his colleagues used graphene to detect differences in the composition of cerebrospinal fluid (CSF) — the liquid that circulates in the brain and spinal cord — from 13 patients with ALS, three with multiple sclerosis (MS), three with a form of neurodegenerative disease that was not ALS, and seven without 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,” he said.

Berry said these CSF biochemical signatures, arising from specific combinations of proteins and other molecules that are unique to each individual, can also be picked up by graphene.

“Our findings of the measured differences between ALS and MND [motor neuron diseases] offer a unique strategy to developing a diagnostic biomarker that can be used to distinguish ALS from other forms of motor neuron diseases,” the researchers stated. “[Our] graphene platform cannot only be used to potentially diagnose ALS, but also to monitor its progression and in the future, to study the efficacy of therapeutics,” they concluded.