Graphene Magnetic Sensors (GMS) represent a cutting-edge sensing technology, with applications ranging from environmental monitoring to healthcare diagnostics. These highly sensitive and robust sensors detect changes in the conductivity of graphene when an analyte interacts with the surface – either directly or indirectly – through a charged double layer of ions at the solid-liquid interface. This sensitivity towards surface modification makes GMS suitable for ion, pH, gas and even biomolecule sensing.
GMS have proven versatile across industries. From detecting hydrogen sulfide contamination in hydrogen gas for environmental monitoring to potentially managing chronic diseases in healthcare, GMS offer multi-use solutions tailored to diverse applications. They can function as durable, long-term sensors or as disposable single-use devices designed for biofluid compatibility, positioning GMS as a flexible diagnostic and monitoring platform.
Leveraging Graphene’s Unique Properties & Overcoming Manufacturing Challenges
The core of GMS’s capabilities lies in their active graphene sheet. Graphene’s exceptional electrical conductivity and charge carrier mobility enable the detection of subtle changes in charge associated with analytes. This combination supports applications requiring both precision and flexibility.
Bare graphene can detect small molecules; but adding a selective membrane enhances specificity, enabling the detection of targeted ions or molecules even within complex backgrounds. The graphene surface serves as a robust yet sensitive platform for functionalizing with a variety of binding molecules, polymers, or metal oxides, offering nearly endless customization possibilities.
Paragraf’s GMS are free from defects and contamination (copper and organic residues) due to the metal-organic chemical vapor deposition (MOCVD) fabrication process that avoids transfer, ensuring that the sensor will perform as intended – consistently – even at high production volumes. The sensor elements are provided as a ‘blank canvas’ that can be functionalized by the user for any application, making it tailorable to individual needs. Furthermore, its physical design has been created specifically for the user to undertake such modifications by hand, avoiding the requirement for expensive deposition equipment for initial evaluations. The GMS market is still in its infancy, but there are several key application areas that are currently being established.
Key Applications of GMS Technology
Ion Sensing
Ion sensing is among the most-accessible applications for GMS, as graphene can be functionalized with selective membranes or receptors. These membranes contain ionophores embedded within a polymer layer, enabling specificity toward target ions. The strong signal response of single ions across the graphene sheet — up to a 200mV shift in the Dirac point — ensures high sensitivity and a low signal-to-noise ratio.
Potassium and calcium ion sensing are especially relevant for healthcare applications. These ions are critical biological micronutrients, with deviations from normal levels posing significant health risks for conditions like renal disease, heart failure and high blood pressure. GMS offer the potential for rapid, precise monitoring of these ions, enhancing disease management and diagnosis.
pH Sensing
GMS excel in pH sensing, with applications spanning industrial processes, healthcare and environmental monitoring. Their robustness and compact size make them particularly valuable in harsh industrial environments, where traditional bulky pH probes may struggle. By digitizing pH measurements with GMS, industries can benefit from enhanced accuracy and reduced calibration requirements.
Gas Sensing
Gas sensing bridges the gap between single-molecule and larger-molecule detection, with GMS delivering a strong signal response to gases like acetone, hydrogen and methane. Applications include early detection of respiratory infections (via acetone) in breath, monitoring hydrogen sulfide in hydrogen gas and measuring methane emissions in agricultural environments. While gas sensing entails additional considerations due to the electrolyte-gated mechanism, GMS have demonstrated promising results across diverse use cases.
Emerging Applications in Agriculture
GMS hold untapped potential in agriculture, from detecting fertilizer runoff and heavy metals in water to monitoring greenhouse gas emissions. GMS-based sensors could also play a role in testing genetically modified organisms (GMOs) or identifying contaminants in agricultural products, showcasing their versatility for future applications.
The Future of Multiplex Sensing in Healthcare
A transformative opportunity for GMS lies in multiplex sensing—integrating multiple sensing channels into a single chip to detect various biomarkers simultaneously. This capability could revolutionize diagnostics, particularly in regions with limited access to healthcare. For example, a single GMS-based platform could test for HIV, malaria and other infectious diseases using a small blood sample, and could deliver the results of those tests on-site, in minutes, obviating the need to send samples to a lab.
Such systems would enable fully digitized health monitoring, providing clinicians with precise data for decision-making. However, scaling production and reducing costs remain critical for widespread adoption. Advances in manufacturing aim to achieve disposable GMS sensors priced below $1, with production volumes exceeding one million units annually.
Paragraf has a direct line to this price point in large volume with die measuring below 3 mm x 3 mm. Supplying the graphene sensor elements that can then be functionalised by the end-user mean that individual requirements for customising the receptors on the different GMS channels won’t slow production down. There is the potential for graphene to revolutionise mass healthcare and provide a way to detect multiple medical conditions in a digitised way, using the data collected from these sensors to drive treatment decision making and healthcare outcomes.
Paragraf understands that this requires more work and time to come to fruition, but we’re confident in our positioning that the opportunity for many to bring better health and disease management to the world could be brought about by graphene―starting at Paragraf’s state-of-the art facility in Huntingdon.
A Promising Horizon 
GMS are poised to reshape sensing technology across industries. Their adaptability, sensitivity and scalability make them invaluable for academic researchers, industrial developers and healthcare professionals alike. As the technology matures, its potential to enhance diagnostics and monitoring will continue to grow, driving innovation in science and industry.
To understand more about how Paragraf plans to revolutionise sensing technology or to find out more about how out GMS can be developed to provide enhanced sensing capabilities to your processes, contact our technical team today―and they will lead you through the steps towards getting equipped with a robust sensing platform where you can build and develop your own individual sensing solutions.
