The benefits of carbon nanostructures in biosensors and healthcare

Carbon nanostructures have become vital in enhancing the precision, sensitivity and miniaturisation of biosensing technologies. With unique electrical, mechanical and surface properties, materials like graphene, carbon nanotubes (CNTs) and graphene oxide (GO) have become integral for the next-generation biosensors. Their applications extend across real-time disease detection, chronic condition monitoring and wearable diagnostics to bridge fundamental materials science with translational medicine.  

However, whilst traditional nanomaterials offer substantial advantages, they are not without technical and practical limitations, particularly around scalability, surface functionalisation, and biocompatibility. In this article, we examine the strengths of carbon nanostructures and their impact on biosensor innovation, as well as their weaknesses and how to overcome them. 

The types of carbon nanostructures in detail

Carbon nanomaterials used in biosensors exist in a variety of forms, each with distinct structural characteristics and functional implications.

Graphene

Graphene is a single layer of sp²-hybridised carbon atoms arranged in a two-dimensional honeycomb lattice. Its outstanding electrical conductivity facilitates rapid electron transfer, which enhances the signal-to-noise ratio in electrochemical sensors. Graphene also offers a large specific surface area, allowing high-density biomolecule immobilisation for increased detection sensitivity. Its mechanical flexibility and transparency make it ideal for integration into wearable platforms. In biosensing, graphene enables ultra-sensitive detection of analytes ranging from proteins and nucleic acids to hormones, even at femtomolar concentrations.

Carbon nanotubes (CNTs)

CNTs are cylindrical nanostructures derived from rolled graphene sheets, available as single-walled (SWCNTs) or multi-walled (MWCNTs) variants. Their exceptional tensile strength, electrical conductivity and chemical inertness make them valuable transducers in biosensors. CNTs can be functionalised with a variety of biorecognition elements, enabling detection of glucose, DNA, cytokines and more. Their unique structure makes CNTs valuable for amperometric biosensors and field-effect transistors used in disease diagnostics and neural monitoring. 

Graphene oxide (GO)

GO is an oxidised derivative of graphene that contains a range of reactive oxygen functional groups. Although GO has reduced conductivity compared to pristine graphene, it is often employed in sensors where functionalisation and biocompatibility are prioritised. GO-based sensors have been successfully deployed for certain applications like nucleic acid detection. Reduced graphene oxide (rGO) provides a tunable trade-off between conductivity and functionalisation potential, making it a popular choice for composite biosensor platforms.

Real-world healthcare applications of carbon nanostructures 

Carbon nanostructures such as graphene, carbon nanotubes (CNTs) and graphene oxide (GO) have transitioned from laboratory research to tangible healthcare applications. Their exceptional properties have been harnessed in various medical domains, including diagnostics, therapeutics and regenerative medicine. 

• Cancer biomarker detection: Graphene-based biosensors have been developed for the detection of cancer risk biomarkers. For instance, epitaxial graphene on silicon carbide has been utilised to detect 8-hydroxydeoxyguanosine (8-OHdG), a DNA damage biomarker associated with increased cancer risk. These sensors offer high sensitivity and specificity, facilitating early diagnosis and monitoring of cancer progression. ​
• Glucose monitoring: Graphene oxide (GO) has been widely employed in the development of biosensors for glucose detection. The presence of oxygen-containing functional groups in GO allows for effective immobilisation of glucose oxidase enzymes, leading to enhanced sensitivity and selectivity in glucose monitoring devices.
• DNA detection: Functionalised CNTs serve as platforms for detecting specific DNA sequences. By attaching single-stranded DNA probes to CNTs, these biosensors can identify complementary DNA strands through changes in electrical conductivity, aiding in genetic disorder diagnostics and pathogen detection.

The unfortunate limitations of traditional carbon nanostructures 

Despite their advantages, carbon nanostructures face several critical challenges when it comes to biosensing. As their use moves from research labs into commercial and clinical applications, these challenges become increasingly important to address to ensure widespread adoption and reliability.

• Scalability: High-quality production methods like chemical vapour deposition (CVD) for pristine graphene are expensive and limited in yield.
• Cost: Sophisticated purification and functionalisation steps increase material costs, limiting widespread adoption.
• Functionalisation complexity: Covalent modification for functionalisation can impair conductivity, whilst non-covalent methods require precise control to ensure stability and reproducibility.
• Biocompatibility and fouling: Carbon materials can adsorb non-specific proteins, leading to signal drift. Although antifouling coatings can help, long-term biofouling remains a challenge.
• Standardisation: Variability in nanomaterial quality from batch to batch hinders regulatory approval and commercial integration. 

Realising the full potential of carbon nanomaterials

Carbon nanostructures like graphene, CNTs, and GO have undeniably changed the design and performance of biosensors in healthcare. They enable ultra-sensitive detection, multiplexing, miniaturisation, and integration into flexible, wearable formats. Yet, limitations in scale, stability, and surface chemistry optimisation continue to restrict their full potential.

This is where Gii steps in as a proprietary nanomaterial. Engineered to overcome these bottlenecks, Gii is a 3D carbon nanomaterial that balances conductivity, surface area and functionality with scalability and low biofouling. Whether you're building the next-gen diagnostic platform or looking to transition from lab to clinic, Gii is your partner in performance.

Download our guide below to discover how Gii solves the toughest challenges in biosensor innovation.