Advanced carbons in sensors

Graphene is the most active in-scope carbon in sensing, because every atom sits on the surface, so adsorption of a single molecule changes its resistance measurably. Combined with high carrier mobility and tuneable resistance, this suits chemical, biological, pressure, strain and gas sensors, with graphene field-effect devices demonstrating parts-per-billion sensitivity to gases such as nitrogen dioxide at room temperature and faster response than metal-oxide sensors. As piezoresistive films, graphene strain gauges reach gauge factors above 1,000, against about 2 for metal foil.

Carbon nanotubes and graphene provide electrochemical electrode surfaces in diagnostic biosensors, detecting glucose, lactate, uric acid and pathogens through redox signals in wearable and implantable formats. Emerging nano carbons such as graphene and carbon quantum dots give tuneable fluorescence for optical, pH and ion sensing, with emission tunable across 400 to 700 nanometres by particle size. MXenes are emerging as high-surface-area electrochemical electrodes for heavy-metal and antioxidant detection in water and food.

The graphene sensors market was valued at about $493 million in 2024 and is growing at roughly 32% a year to 2029. Carbon nanotube biosensors sit within a single-walled carbon nanotube market of about $410 million in 2024, and sensing is one of the fastest-growing uses inside a carbon nanomaterials market valued at about $2.2 billion. MXene electrodes already featured in roughly 18% of sensor research in 2024, an early indicator of commercial potential.