Using graphene to develop highly sensitive & fast point-of-care diagnostic devices

Jul 31, 2023 | Knowledge Center

Picture of General Graphene’s GG 3.0 graphene synthesis equipment with inline polymer spray coating system.

A Lack of Preparedness

Global healthcare faced its biggest test during the COVID-19 pandemic, with the lack of advanced medical infrastructure and reliable testing tools leading to the unrestrained spread of the virus across the world.

One of the biggest issues highlighted during the pandemic was the ability to detect COVID-19 accurately at the point-of-care. While industry responded rapidly to the pandemic’s arrival by deploying a variety of point-of-care lateral flow devices within a few months, limitations in sensitivity and selectivity prevented these tools from being accurate and reliable enough to mitigate the spread of the COVID-19 virus. In fact, most airlines that required a negative COVID-19 diagnosis before flight departure refused to accept anything other than PCR due to the inaccurate and unreliable nature of point-of-care lateral flow devices.

The poor reliability of point-of-care devices meant that market perception shifted towards PCR as the only way forward. However, PCR has its own set of difficulties – including the inability to deploy at the point-of-care, the requirement for extensive sample preparation, and signal amplification. The need was clear – diagnostic tests would have to be deployed at the point of care and be accurate enough to effectively contain infectious disease outbreaks.

Why Graphene?

Graphene is a platform material that lies at the intersection of biology and technology with potential for incorporation across a variety of biosensing platforms. Biosensor platforms serve as portable electrochemical devices that measure biomolecule interactions by generating a signal based on the introduction of a target biorecognition element – such as antibodies, enzymes, proteins, viruses, aptamers, etc. Functioning as “lab-on-a-chip” devices, graphene-based biosensors offer key advantages in speed, accuracy, and point-of-care deployment that make it a unique solution geared towards solving some of the biggest challenges in healthcare. Graphene’s ability to provide rapid sensitive detection of various biomarkers is poised to deliver significant advancements in early disease diagnosis, personalized medicine, and biomedical research.

A surface chemist or biological surface engineer can take a surface of graphene and functionalize it using a large variety of biomolecule receptors – proteins, aptamers, viruses, DNA, RNA, antibodies, etc. Graphene’s wide functionalization potential enables it to be utilized across a variety of single or multiplexed point-of-care biosensor devices. Atomically thin materials present unique properties due to the laws of quantum mechanics coming into effect. Graphene’s unique electrical properties play a key role in enabling high sensitivity detection of biomolecules in an affinity-based field-effect transistor (FET) device configuration. Most existing point-of-care diagnostic tools are limited to 10-9 or nano levels of sensitivity in detection. Utilizing CVD graphene, our partners have been able to develop a variety of diagnostic devices that offer between 10-11 to 10-15 levels of sensitivity – an unprecedented improvement over traditional point-of-care diagnostic devices and superior to PCR at 10-15 levels of sensitivity.

With a high signal to noise ratio, graphene-based point-of-care diagnostics ensure high selectivity along with a wide detection range of analyte concentrations. This is crucial towards mitigating the large number of false positives and false negatives visible across traditional point-of-care tools, and ensuring that graphene-based point-of-care diagnostics possess accuracy on par or better than lab-grade diagnostic tools.

Most lab-based screening tools also require signal amplification and/or extensive sample preparation to provide accurate detection of biomolecule concentrations. Graphene-based point-of-care diagnostics eliminate the need for signal amplification entirely and require minimal sample preparation to provide accurate biomolecule concentration results. This helps reduce the time to results significantly – from several days and hours to mere minutes.

Preparing for the Next Pandemic

What if graphene-based point-of-care devices had existed during the COVID-19 pandemic? The benefits described would have undoubtedly played a pivotal role in addressing numerous challenges associated with disease management, potentially leading to better control and containment of the global COVID-19 outbreak. People would not have to drive up to a PCR testing facility for reliable and accurate testing – reducing risk of further contamination and thereby potentially helping contain the outbreak.

With their high selectivity and signal-to-noise ratio, graphene-based biosensors could also mitigate the number of false positives and false negatives, thereby improving the overall credibility of point-of-care diagnostic platforms. The ability to provide fast point-of-care detection with results delivered in minutes could have also allowed for timely contact tracing and isolation – significantly reducing the testing backlog medical providers faced during the pandemic.

It is certain that the world needs to be better equipped before the next pandemic sets in. Graphene biosensors have the potential to become a critical element towards developing improved healthcare technology and infrastructure that can help contain future infectious disease outbreaks.

Graphene’s Impact Beyond COVID-19 Diagnostics

Graphene’s versatile functionalization potential means that its potential in point-of-care diagnostic devices extends far beyond COVID-19. We are partnering with GrapheneDx who are developers of novel graphene-based diagnostic platforms. Their first device in development is a multiplexed point-of-care device capable of high sensitivity detection of chlamydia and gonorrhea within minutes – widening the landscape of accurate real-time STD testing beyond clinical settings.

Figure 1 – GrapheneDX’s graphene diagnostic platform for multiplexed point-of-care STD testing[1]

“Hememics Biotechnologies is a partner developing 32-plex graphene biosensor chips that are 100 times more sensitive than lateral flow devices. Their first set of graphene devices are geared towards detecting SEB and ricin at consistent low picomolar range sensitivities with results provided within 5 minutes – providing a field deployable tool for real-time biotoxin detection.”

 

Figure 2 – Hememics Biotechnologies’s 32-plex graphene biosensor chip devices[2]

Beyond diagnostics, graphene-based biosensors can be utilized in real-time environmental monitoring applications, real-time monitoring of vital signs (glucose levels and heart rate), food safety and agriculture, and in biomedical research to measure various biomolecular interactions – including protein-protein interactions, DNA hybridization, enzyme kinetics, etc. Graphene’s versatility as a platform material and its immense potential for functionalization make it a promising candidate for biomolecule sensing across several applications. Its exceptional electrical properties and extensive customization possibilities offer extensive opportunity for exploration and innovation in this field, driven by the creative thinking and expertise of skilled biological surface engineers.

Scalable Graphene Biosensors

Our belief is that to make an impact and be ready for mass adoption, graphene-based solutions must be cheaper and better than existing alternatives. Our industrial-scale CVD graphene manufacturing technology allows us to provide CVD graphene in mass volumes, at significantly lower price points, and tailored qualities for specific applications. This enables the incorporation of CVD graphene across point-of-care diagnostic tools that are at least 100 times more sensitive and cost competitive relative to thin film metal substitutes.

By enabling the manufacturing of low-cost point-of-care diagnostics with lab-grade accuracy and fast time to results, graphene offers a pathway towards developing a safe and convenient healthcare ecosystem for users and healthcare providers alike. With our industrial-scale CVD technology, we are confident in our ability to provide CVD graphene materials to our partners and collaboratively tackle the challenge of scaling CVD graphene application development R&D.

To learn more about how our industrial-scale CVD graphene materials can help scale graphene biosensor development, read our white paper on CVD graphene in biosensors. Contact us if you are interested in working with our CVD graphene materials for your biosensor application.

[1] Photo by GrapheneDX.

[2] Photo by Hememics Biotechnologies Inc.