Graphene sensors: introduction and market status

First Graphene has signed a 36-month strategic partner agreement with UK-based Vector Companies Group Limited, expanding its commercial distribution into the global heat flux sensor market.

The agreement coincides with Vector's launch of Peltyr, a new line of printed heat flux sensors incorporating First Graphene's PureGRAPH material. The sensors measure real-time thermal performance and heat transfer rates (in-situ U-values) through building fabric such as walls, roofs, and floors, offering a direct measurement alternative to theoretical modeling during energy-efficiency retrofits.

Researchers at the University of the Bundeswehr Munich, with contributing researchers from Friedrich-Alexander-Universität Erlangen-Nürnberg and other international collaborators, have developed a graphene-based transistor that detects the stress hormone cortisol directly in human saliva, with results matching a standard lab test.

The device is an electrolyte-gated graphene field-effect transistor (EG-GFET) built on CVD-grown graphene. The graphene channel is functionalized with perylene bisimide (PBI) linker molecules using the team's own functional layer-assisted transfer (FLaT) method, which both anchors the sensing chemistry and shields the graphene from ambient contamination. Antibody fragments (Fab) targeting cortisol are then covalently attached to the PBI layer, giving the sensor a label-free way to detect the hormone: when cortisol binds to the immobilized Fab fragments, it shifts the transistor's Dirac point, producing a direct electrical readout.

Researchers at Peking University, Jiangxi Normal University, the University of Science and Technology Beijing, and the University of Bristol have developed a liquid crystal elastomer (LCE) actuator reinforced with thiol-functionalized graphene oxide (FGO) that combines high mechanical toughness with an activation temperature close to human body temperature, addressing a longstanding tradeoff in soft robotics materials.

Illustration of the graphene oxide-reinforced liquid crystal elastomer actuator, showing its near-body-temperature activation and high fracture toughness.

Liquid crystal elastomers are widely studied for soft actuators and artificial muscles because they can undergo large, reversible, programmable deformations in response to heat, light, or other stimuli, and graphene oxide fillers have previously been used to boost their toughness through strong π-π interactions with the liquid crystal phase. But conventional LCEs face a persistent conflict: actuators tough enough for demanding, high-load robotic applications typically require activation temperatures above 100°C, which is impractical and potentially unsafe for devices meant to interact directly with the human body, while LCEs engineered for near-body-temperature activation have generally lacked the mechanical robustness for real-world use.

Researchers at Silicon Austria Labs (SAL) and EPFL have developed a recyclable, surfactant-free graphene nanoplatelet (GNP) ink that uses linalool ,a terpene alcohol that occurs naturally in lavender, basil and other aromatic plants, as its solvent and ethyl cellulose as its binder. The team printed electrochemical sensors with the ink, then took them apart after use. They recovered more than 93% of the graphene, along with the solvent and the PET substrate, and used them to print new devices. The ink went through five consecutive recycling cycles without a drop in performance.

Schematic of the closed-loop recycling system: the graphene ink is used to print electrochemical sensors, and after recycling, the recovered material is reused to print new sensors and heaters. Image from: Communications Sustainability

Most high-performance conductive inks still depend on petrochemical solvents such as NMP, DMF and toluene, several of which are classified as carcinogenic, mutagenic or reprotoxic. They also use synthetic binders that make material recovery difficult. Earlier recycling approaches for printed electronics have typically recovered only part of a device, often by using corrosive solvents that destroy the substrate, or by reclaiming the conductive ink while leaving other layers contaminated.

Researchers at Universidad Técnica Particular de Loja, Escuela Superior Politécnica de Chimborazo (ESPOCH), Università della Calabria, and Universidad Ecotec have computationally designed and optimized a surface plasmon resonance (SPR) sensor for detecting trace mercury, lead, and zinc ions in water, using a graphene oxide sensing layer atop an aluminum/aluminum oxide plasmonic stack on a borosilicate glass prism.

Schematic representation of the borosilicate-supported (B-sil)/Al/Al₂O₃/nanomaterial SPR sensor. Image from: Electron

The team compared four carbon nanomaterials as candidate sensing layers: graphene oxide, reduced graphene oxide, pristine graphene, and semiconducting single-walled carbon nanotubes, and evaluated each for angular sensitivity, resonance linewidth, and detection limit using transfer-matrix modeling. While single-walled carbon nanotubes and reduced graphene oxide produced larger angular shifts, both introduced severe resonance broadening. Graphene oxide offered the most balanced response: a measurable resonance shift combined with a comparatively narrow, well-defined resonance dip.

Researchers at Stony Brook University, part of the State University of New York (SUNY) system, have patented a new method for measuring dew point and detecting icing conditions using a graphene oxide film, offering a potentially far cheaper alternative to the expensive chilled-mirror hygrometers currently used for precision humidity measurement.

Dew point - the temperature at which moisture in the air begins condensing on a surface - is considered a more reliable humidity metric than relative humidity, since it stays constant regardless of temperature changes. Chilled-mirror hygrometers, which cool a surface to find that exact condensation point, are regarded as the most accurate instruments for the job and are widely used in labs and industrial settings requiring precise, repeatable humidity control. However, these laboratory-grade instruments are notoriously expensive and can be temperamental in operation.

Researchers at the Daegu Gyeongbuk Institute of Science and Technology (DGIST), Hanbat National University, Chungnam National University, the Korea Institute of Industrial Technology, Kyungpook National University, and the Gumi Electronics and Information Technology Research Institute (GERI) have developed a hierarchical graphene nanowall (GNW) "nanomesh" that delivers up to six times the sensitivity of conventional planar graphene gas sensors, while remaining flexible and breathable enough for wearable use.

Wearable gas sensors need to operate sensitively at room temperature while staying mechanically compliant for long-term wear, but most existing designs rely on planar sensing layers that limit accessible surface area. Vertically oriented graphene nanowalls offer an edge-rich, high-surface-area alternative, but growing them conventionally requires temperatures above 600°C, incompatible with flexible polymer substrates — and transfer-based workarounds keep the resulting structure planar rather than truly three-dimensional. The team's solution was a "3D-on-3D" architecture: graphene nanowalls grown directly onto a three-dimensional polymer nanofiber nanomesh rather than a flat film. An electrospun polyamic acid nanomesh was converted to polyimide, coated with a thermally robust parylene layer, and given a thin SiO₂ nucleation layer, allowing vertically oriented GNWs to be grown across the fiber network via low-temperature plasma-enhanced chemical vapor deposition without collapsing the underlying scaffold.

Researchers at the National University of Singapore, the Center for Neurophysics and Neuromorphic Technologies (Moscow), Queen's University (Kingston), HSE University (Moscow), the National Institute for Materials Science (Tsukuba) and the University of Manchester, have shown that magic-angle twisted bilayer graphene (MATBG) can be switched from an insulating to a metallic state by exposure to very weak far-infrared (FIR) radiation, opening a path toward ultrasensitive detectors for one of the least-exploited bands of the electromagnetic spectrum.

MATBG is formed by stacking two graphene sheets with a relative twist of about one degree. At this "magic" angle, the electronic bands narrow dramatically, strengthening interactions between electrons. Under the right gate voltage, these interactions produce a correlated insulator - a fragile collective electronic state in which conduction is strongly suppressed, distinct from an ordinary band insulator.

Researchers at Italy's National Research Council (CNR) - specifically its Institute for Organic Synthesis and Photoreactivity (Cnr-Isof) and Institute of Nanostructured Materials (Cnr-Ismn) - working with Ca' Foscari University of Venice, the University of Ferrara, and the University of Bologna, have developed a graphene-based bioelectronic platform that combines sustainable materials, biochemical sensing, and neural stimulation in a single biodegradable device, aimed at both monitoring and modulating activity in brain tissue.

The platform is built from poly(lactic acid) (PLA) and graphene oxide, processed through a green, water-based manufacturing route and turned into conductive electrodes through laser functionalization rather than more environmentally costly fabrication methods. The approach is meant to address the growing footprint of implantable and wearable medical electronics by keeping the device fully biodegradable and biocompatible while still delivering the electrical performance needed for neural interfacing.

UK-based Paragraf has launched two new products expanding its graphene sensing portfolio: the PMF2002 Graphene Field-Effect Transistor (GFET) Platform and the Enterprise Reader data acquisition system, designed to work together to take users from sensor development through to data analysis.

The PMF2002 builds on Paragraf's earlier PMF2000 platform with a 12-channel multiplexing architecture that uses a common gate with separate source and drain connections, allowing simultaneous measurements across multiple sensing channels from a single sample while requiring less sample material. The sensing surface can be functionalized by customers, letting the platform be adapted for target-specific detection across applications including water quality monitoring, soil analysis, gas detection, and molecular biosensing.