Enzyme-linked immunosorbent assay (ELISA) is a foundational analytical technique in biomedical and human diagnostics. It is employed extensively for the detection and quantification of proteins, hormones, antibodies and cytokines. Since its development in the 1970s, ELISA has been responsible for countless assays due to its specificity, adaptability and relatively straightforward implementation within controlled laboratory environments.
However, the demand for decentralised, point-of-care (POC) diagnostics in both clinical and non-clinical settings has led to the scrutiny of traditional ELISA methodologies. Questions around the viability of digitalising ELISA (particularly through electrochemical platforms) are being met with alternatives that take minutes to perform assays rather than hours.
As demand shifts toward real-time, on-site molecular diagnostics, attention is increasingly turning to electrochemical platforms that offer the precision of ELISA with the speed and portability modern workflows require.
The Enzyme-Linked Immunosorbent Assay (ELISA) is a widely used analytical technique for detecting and quantifying soluble targets such as proteins, peptides, hormones and cytokines. It works by coupling antigen–antibody recognition with enzyme-mediated signal amplification and optical detection.
ELISA tests are analytically robust and have been used extensively, but they also present several well documented limitations. Their workflows are time-intensive, often requiring multiple binding, washing and incubation steps that stretch assay times to several hours. ELISA tests also require skilled technicians to manage protocol complexity tied to factors like timing and temperature control. Additionally, these tests require bulky infrastructure like microplate readers and temperature controlled incubators. All of these factors combined make ELISA tests largely inaccessible out of centralised labs and almost impossible to digitise.
A critical component of electrochemical biosensors is the electrode material, which acts as the transduction interface. Materials like graphene and carbon nanotubes (CNTs) have been widely explored due to their conductivity, surface-area-to-volume ratio and biocompatibility. Graphene-based electrodes in particular have enabled impressive improvements in analytical sensitivity and miniaturisation.
However, despite these advantages, graphene-based sensors face persistent limitations that prevent them from replacing ELISA at scale.
Emerging next-generation carbon nanomaterials have been developed to bridge the gap between the lab-scale performance of graphene and the real-world requirements of scalable diagnostics. These new materials retain and exceed the desirable electrochemical properties of graphene but overcome key challenges in manufacturing and functionalisation.
By avoiding covalent modification and instead leveraging π–π stacking interactions (e.g., using pyrene derivatives), these materials maintain the structural integrity of the carbon lattice while enabling stable and efficient biorecognition element attachment. This supports label-free detection and rapid electron transfer, even in complex biological fluids like saliva, serum and plasma. On top of that, these new carbon nanomaterials provide a number of additional benefits.
These properties make them uniquely suited for integration into disposable, digital biosensor platforms offering laboratory-grade analytical power in a portable, point-of-care-compatible format.
ELISA is still considered a laboratory gold standard, but its limitations in decentralised settings are clear. Electrochemical biosensors present a faster and scalable alternative, but only when built on materials that overcome the challenges of functionalisation and scalability
Gii is that material. Engineered for performance in complex fluids, Gii offers ultra-low detection limits, extremely fast assays and anti-fouling behaviour, all in a format that’s scalable, sustainable and cost-effective.
For teams developing the next generation of digital diagnostics, Gii provides a practical path to ELISA-grade performance and more. Download our guide to learn how Gii accelerates electrochemical biosensor development.