Liz Meszaros, MDLinx | March 19, 2019
The “supermaterial” graphene may be the key to advanced detection of early-stage lung cancer in the future, according to researchers from the University of Exeter, United Kingdom. They recently developed a highly sensitive graphene biosensor that can detect common lung cancer biomarkers, and published their results in Nanoscale.
Cancer-marker (CM) monitoring is a promising area wherein researchers hope to detect the CMs present in exhaled volatile organic compounds (VOCs) that are emitted during breathing. These VOCs essentially comprise a “breath-print.”
“Diagnosis of lung cancer or any type of disease through a non-invasive e-nose approach can guarantee a practical and reusable method of complex monitoring of VOCs in the human breath. In this work, we report the feasibility of bare multi-layer graphene (MLG) as a proof of concept for the e-nose technologymulti-layer graphene,” wrote co-author Ben Hogan, postgraduate researcher, University of Exeter, and fellow researchers.
“The new biosensors which we have developed show that graphene has significant potential for use as an electrode in e-nose devices. For the first time, we have shown that with suitable patterning graphene can be used as a specific, selective and sensitive detector for biomarkers. We believe that with further development of our devices, a cheap, reusable and accurate breath test for early-stage detection of lung cancer can become a reality,” added Hogan.
But first, what is graphene?
Graphene is a single, thin layer of graphite, commonly used in pencil lead. As an allotrope of carbon, graphite has the same atoms but, because they are arranged differently, graphite’s properties differ from carbon’s.
Graphene is one of the strongest materials in existence, with a tensile strength of 130 gigapascals—that’s 100 times stronger than steel. It has several advantageous characteristics: a large surface area, great electrical conductivity, is stable, does not degrade over time, and is flexible, as well as transparent.
In medicine, particularly, the potential of graphene is impressive. For example, small machines and sensors made of graphene can move effortlessly throughout the body, to analyze tissues and even deliver drugs to targeted areas, all without causing harm.
Now, what are e-nose devices?
Several e-nose breath sensors have been developed to analyze VOCs. E-nose devices combine electronic sensors equipped to recognize patterns, like a neural network.
In this study, Hogan and fellow researchers measured graphene’s ability to sense CMs in a range of concentrations electronically. When they equipped e-nose devices with MLG electrodes, the results were extraordinary.
They found that patterned MLG electrodes enhanced sensitivity for three of the most common lung-cancer biomarkers—ethanol, isopropanol, and acetone—in differing concentrations.
“We show promising sensing capabilities for [MLG] for biomolecule discrimination of common lung CMs such as ethanol, isopropanol, and acetone,” concluded Hogan and colleagues.
They are hopeful that their discovery will pave the way for new and improved e-nose devices capable of detecting lung cancer much earlier than previously possible. Their newly developed, reusable device may have the capability to identify—at very early stages—specific lung CMs conveniently and accurately.