Researchers developed a new coating using bovine serum albumin (BSA) and functionalized graphene to prevent biofouling and suppress immune responses that typically limit the lifespan of biosensors. [Image courtesy of the researchers]
The researchers suggest that the technology could continuously monitor disease-related biomarkers over extended periods.
The new coating comprises a cross-linked lattice of bovine serum albumin (BSA) and functionalized graphene to prevent biofouling and suppress immune responses that typically limit the lifespan of biosensors. In a proof-of-concept study, the team demonstrated that sensors coated with this technology maintained functionality for over three weeks while accurately detecting two inflammatory biomarkers. The findings were published in the journal Biosensors.
“With this novel coating technology, which can offer durable protection of implantable biosensor devices, we have removed a central bottleneck in the development of next-generation electrochemical in vivo sensors,” said Wyss Institute Founding Director Dr. Donald Ingber, who led the study.
“In the age of personalized medicine and digital health, it brings a plethora of diagnostic and research applications within reach,” he continued. “It is also a testament to the laser-sharp focus of the Wyss’ electrochemical sensor team on solving problems that significantly slow progress in clinical care.”
Overcoming biofouling and immune responses
Biosensors have helped improve the management of chronic conditions and enabled real-time monitoring of physiological signals. For example, biosensors are used in continuous glucose monitors and devices that detect electrolytes or inflammatory markers.
However, their effectiveness is often limited by biofouling, or the buildup of bacteria, human cells, and molecules from biofluids that obstruct the sensor’s interaction with target analytes. Additionally, implantable sensors can trigger a foreign body response, activating pro-inflammatory immune cells and forming fibrotic tissue, further reducing sensor performance.
The Wyss team addressed these issues by designing a coating that prevents contamination and immune activation. The BSA lattice forms a natural barrier that blocks the non-specific binding of biofluids and contaminants, while the functionalized graphene ensures efficient electrical signaling. The coating also allows for the stable inclusion of analyte-detecting antibodies and antibiotic agents, which actively combat biofouling.
The team tested the coating on electrochemical sensors designed to bind and detect two key inflammatory biomarkers. The sensors maintained full functionality over three weeks of exposure to complex human plasma and consistently produced accurate readings.
During the same period, the coating resisted the formation of biofilms by P. aeruginosa, a bacterial species known for forming antibiotic-resistant biofilms on medical devices. It also prevented fibroblast adhesion and kept immune cells from triggering a pro-inflammatory response.
According to the researchers, the coating has the potential to improve the longevity and reliability of implantable biosensors used in clinical research and diagnostics. Longer sensor lifespan could enable extended monitoring of patients with chronic or autoimmune diseases and improve the assessment of patient responses to therapies in clinical trials.
The researchers designed the coating to be fabricated using a scalable and cost-effective process, making it suitable for integration into future sensor designs. The materials used in the coating are readily available, and the fabrication process is adaptable for producing biosensors in larger quantities, the researchers said. The Wyss Institute has patented the coating technology and is seeking industry partners to advance its development for real-world use.
