Graphene’s superior utility within the fabrication of nanoscale biosensors has been explored extensively by a variety of researchers and a assessment revealed within the journal, Nanotechnology Evaluations. 

Examine: Graphene-Primarily based Biosensors for Illness Theranostics: Improvement, Functions, and Current Developments. Picture Credit score: luchschenF/Shutterstock.com

Graphene has gathered rising consideration over current years with its use in varied purposes on account of exceptional attributes, and this has additionally branched into revolutionary sensing platforms.

Why Novel Biosensors are Wanted

Biosensors are important for diagnosing illness as they’ll make contact with vital biomarkers that enable for ailments to be recognized in sufferers, permitting efficient administration and therapy.

Standard approaches to establish ailments embody however aren’t restricted to polymerase chain response (PCR), lateral move immunoassay, DNA sequencing and microarrays, and enzyme-linked immunosorbent assay (ELISA).

Whereas these strategies could be efficient with correct and delicate detection of illness markers resulting in diagnoses, they maintain vital limitations that lower their use effectivity. These limitations embody requiring extremely exact and costly devices and reagents and preparations steps which might be advanced and time-consuming. 

Nevertheless, revolutionary approaches that make the most of sensors could be extra advantageous on account of being cheap, easy with out invasive procedures, and having extremely particular strategies which might be efficient for detecting goal biomolecules. Moreover, these novel sensors can be utilized for early illness prognosis additional enabling ailments to be managed and handled successfully, in addition to being able for use in real-time for the monitoring and prognosis of illness, deeming them to be extra helpful in a wider vary of purposes.

Graphene Incorporation into Biosensors

The novel nanomaterial, graphene was first found by Andre Geim and Kostya Novoselov in 2004 and is a carbon allotrope nanomaterial fashioned of a single layer of graphite with atoms organized in a honeycomb lattice.

Its distinctive traits consist of a big floor space, excessive flexibility in addition to efficient digital transportation. The flexibility of graphene includes of its two-dimensional construction, which could be exploited for functionalization with linker molecules that improve its sensitivity and selectivity properties, enhancing its use as a biosensor candidate.

Examples of graphene which were utilized for its biosensing capabilities embody graphene oxide (GO) and decreased graphene oxide (rGO). Graphene biosensors can be utilized for biomedical purposes reminiscent of detecting essential biomarkers to diagnose most cancers formations and cardiovascular ailments.

Using real-time monitoring of illness, reminiscent of using graphene-based electrochemical biosensors for implantable gadgets, can be revolutionary for detecting early biomarkers to forestall illness development. This novel area of theranostics which allows the therapy of ailments with early diagnoses can be a key methodology of enhancing affected person care to a sophisticated degree.

Improvement of Graphene-Primarily based Biosensors

Graphene could be produced by two fundamental approaches, the top-down manufacturing strategy and the bottom-up strategy.

Graphene derivatives could be sourced by varied carbon provides inside the top-down strategy, together with graphite flakes or powder. Graphene could be produced after mechanical or electrochemical exfoliation and chemical oxidation-reduction reactions.

Nevertheless, the bottom-down strategy depends on producing graphene layers from carbon atom bases and might embody quite a lot of strategies reminiscent of chemical vapor deposition or thermal pyrolysis.

The strategy to producing graphene is important as it will probably have an effect on the character of the graphene end result that’s fashioned on the finish, and this may due to this fact affect its traits. When graphene is created for the premise of being a biosensor, its construction can embody a graphene layer that works as a transducer in addition to biomolecules that perform as receptors, reminiscent of antibodies, this may be seen within the visible diagram under.

Graphene biosensor machine which makes use of graphene (transducer) and biomolecules (receptor). ©Alhazmi, H., et al (2021)

Biomolecules such as enzymes, proteins, DNA, and antibodies can be used for specific biorecognition in order to target analytes including biomarkers within a sample. The receptors have a very significant function in being sensitive to physicochemical changes and so can be used to produce a signal when in contact with particular therapeutic targets. 

While other significant functions of graphene in various fields include electronics and healthcare with uses in sensors, quantum dots, novel drug delivery, and others, its role as a biosensor can be used to advance the field of personalized medicine. 

Applications of Graphene-Based Biosensors 

Conventional methods for disease diagnosis as mentioned previously are costly and require complex machinery and reagents, and most significantly, are not quantifiable in real-time. 

The intriguing nature of graphene-based sensors includes a wide range of benefits to biomedical applications and with easy-to-use techniques, cost-efficient, non-toxic and high sensitivity, and selectivity characteristics, this innovation may be revolutionary for enhancing patient care. 

They can be utilized for the detection of various infectious diseases from viruses and bacteria and have successfully been used in research to detect the Ebola virus, E. coli and Zika virus. Additionally, graphene biosensors which were modified with silver and gold nanoparticles were also used in the detection of Salmonella typhimurium, hepatitis-C virus (HCV) and avian influenza virus. 

The ability to modify graphene biosensors can further enhance its use with other proven research illustrating the modification of these versatile biosensors with dendrimers, polymers, and cyclodextrin in order to diagnose celiac disease, human immunodeficiency virus (HIV) and cholera. 

 Some common noncovalent functionalization showing pyrene–graphene, glucose oxidase–graphene, and ssDNA–graphene hybrids. ©Alhazmi, H., et al (2021)

Future Outlook 

The potential of graphene-based biosensors is tremendous and with successful research in this field detecting various infectious diseases, the translation into clinical use would be revolutionary.

 However, with limitations such as its ability to adsorb nontarget molecules may cause false-positive detection, especially if noncovalent functionalization methods are used. Additionally, the incorporation of biomolecules onto the graphene layer may be affected by factors such as temperature, pH, salt concentration, as well as the intrinsic properties of graphene itself. 

This area of research may still have obstacles to climb, however, its significance in theranostics is promising, especially for use as potentially implantable devices for real-time monitoring of disease. 

Applications of biomolecules-immobilized graphene-based biosensors in the detection of target molecules. ©Alhazmi, H., et al (2021)

Reference

Alhazmi, H., Ahsan, W., Mangla, B., Javed, S., Hassan, M., Asmari, M., Al Bratty, M. and Najmi, A., (2021) Graphene-based biosensors for disease theranostics: Development, applications, and recent advancements. Nanotechnology Reviews, 11(1), pp.96-116. Available at: https://www.degruyter.com/document/doi/10.1515/ntrev-2022-0009/html

Further Reading 

Sekhon, S., Kaur, P., Kim, Y. and Sekhon, S., (2021) 2D graphene oxide–aptamer conjugate materials for cancer diagnosis. npj 2D Materials and Applications, 5(1). DOI: https://doi.org/10.1038/s41699-021-00202-7 

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.