What are the best nanomaterials for biosensors?

Nanomaterials have revolutionised biosensor technology, enabling faster, more sensitive and more accurate detection of biological analytes. However, the choice of material can have a major impact on the overall performance of a biosensor, directly affecting its conductivity, biocompatibility, stability and scalability.

Carbon and metallic nanomaterials are commonly used for their conductivity and chemical stability. However, they each come with their own challenges tied to large-scale scalability. In order to choose the best nanomaterial for specific types of biosensors, engineers need to understand the features, benefits and challenges of each in context with biosensing platforms.

Carbon nanomaterials

Carbon-based nanomaterials have garnered significant attention for biosensing due to their electrical conductivity, mechanical strength and large surface area. These properties make them highly suitable for biosensor applications, particularly in electrochemical and optical sensing.

Graphene derivatives 

Graphene is one of the most promising materials for biosensors. It offers high electrical conductivity, a high surface area for biomolecule immobilisation and good mechanical strength. Graphene-based biosensors are applicable for electrochemical and optical sensing applications. However, challenges tied to fabrication and batch-to-batch variability have led to major issues when it comes to scalability, stunting their widespread use in biosensors.

• Benefits: High electrical conductivity, large surface area, good mechanical strength
• Challenges: Fabrication difficulties, batch-to-batch variability

Carbon nanotubes (CNTs)

CNTs, cylindrical nanostructures composed of rolled graphene sheets, provide high electrical conductivity, chemical stability and large surface-to-volume ratios. These properties make CNTs effective in electrochemical biosensors, particularly for detecting biomolecules like glucose, DNA and proteins. However, concerns about biocompatibility and difficulty in functionalisation have greatly limited their widespread adoption.

• Benefits: High electrical conductivity, chemical stability, high surface-to-volume ratio
• Challenges: Biocompatibility concerns, difficulty in functionalisation

Metallic nanomaterials

Metallic nanomaterials are used in biosensors for their unique optical and electrical properties. They enable signal amplification, enhance electron transfer and improve biomolecular interactions through immobilisation, making them valuable in modern biosensing platforms.

Gold electrodes

Gold electrodes are highly conductive and biocompatible, making them a staple in biosensing applications. They facilitate electron transfer in electrochemical sensors and enhance signal amplification in optical biosensors, such as surface plasmon resonance (SPR) assays. Gold electrodes are commonly used in immunosensors and lateral flow assays. Despite their advantages, their high cost and complex synthesis makes large-scale manufacturing a difficult and costly endeavour. 

• Benefits: High conductivity, biocompatibility, signal amplification
• Challenges: High cost, complex synthesis

Silver electrodes 

Silver electrodes exhibit good electrical conductivity whilst being cheaper than gold. In certain optical biosensing environments, silver electrodes offer greater sensitivity than gold alternatives. They are used in optical and electrochemical biosensors for pathogen detection. However, silver electrodes suffer from stability issues due to oxidation and bring potential cytotoxicity concerns which can restrict their use in biomedical applications.

• Benefits: Strong antimicrobial properties, good electrical conductivity
• Challenges: Stability issues due to oxidation, potential cytotoxicity 

Novel nanomaterials 

Novel nanomaterials like Gii have emerged as the leading choice for biosensors, combining high electrical conductivity, exceptional biocompatibility and superior scalability. Unlike graphene derivatives, it eliminates fabrication inconsistencies, and unlike metallic nanomaterials, it offers cost-effective, stable performance. Its three-dimensional porous structure enhances biomolecule immobilisation, while anti-fouling properties ensure accurate detection in complex samples. With reproducible manufacturing and performance surpassing noble metals and carbon competitors, it is the best material for next-generation biosensors.

• Benefits: High electrical conductivity, large surface area, reproducible fabrication, excellent anti-fouling properties
• Challenges: Emerging technology requiring further industry adoption

Choosing the right material for your biosensing application

The choice of nanomaterial plays a crucial role in the development of biosensors, influencing their sensitivity, stability and scalability. Carbon nanomaterials and metallic nanomaterials each have their strengths and limitations. Whilst graphene and gold electrodes have dominated biosensor research, the emergence of a new advanced material has opened new avenues for scalable and commercially viable biosensing solutions. 

Gii is a proprietary carbon nanomaterial that overcomes many of the challenges associated with conventional electrochemical biosensor materials. Unlike noble metals and traditional graphene derivatives, Gii-Sens is highly reproducible, biocompatible and offers anti-fouling properties. These features make it an optimal choice for high-sensitivity electrochemical biosensors as it offers enhanced conductivity and surface area compared to graphene derivatives and is far more scalable.

If you’re developing biosensing technologies and looking for the most effective nanomaterial, find out more about Gii by downloading the data sheet below.