Graphene-Based Diagnostics

Researchers have developed a graphene-based field-effect transistor (GFET) biosensor capable of detecting chemokines, such as CXCL8 (IL-8), with unprecedented sensitivity in clinical samples.

The biosensor combines a single layer of graphene with a thin carbon nanomembrane (CNM) to form a specialized structure. This CNM serves as a connector, enabling the attachment of RNA-based molecules called l-aptamers, which are designed to capture specific chemical signals, such as inflammation-related proteins. These l-aptamers are engineered to resist breakdown by enzymes, making the sensor stable in complex biological samples. To improve accuracy, a coating of polyethylene glycol is added, which reduces unwanted interference from other proteins.

Clinical validation involved nasal swab samples from patients with respiratory infections. Despite sample dilution to reduce mucus viscosity, the sensor maintained its accuracy, detecting CXCL8 concentrations as low as 1 pM – results that were consistent with conventional immunoassays.

The paper’s first author, David Kaiser, said, “This research result could be groundbreaking for the diagnostics of the future, because we have been able to remove a major hurdle on the way to a graphene-based biosensor that is far more effective than anything currently used in normal clinical applications area. It is much more sensitive, significantly faster – the results are available in around five minutes – and cost-effective if it is produced in large quantities.”

The researchers plan to expand the platform to detect other biomarkers, paving the way for multiplexed diagnostics in personalized medicine and broader healthcare settings.