How Would Graphene-Based DNA Biosensors Work?

Jessica Maloney, March 13th, 2020

Biosensors are advanced analytical components designed to detect biological analytes via electro- or physicochemical interactions. Innovations in coupling bioactive interfaces to appropriate transducer elements in recent years, especially among monolayer material offerings, have yielded a dramatic increase in the range of high sensitivity biosensors available to clinical and industrial users. Among these is a novel class of biosensors capable of detecting deoxyribonucleic acid (DNA).

What are DNA Biosensors?

DNA biosensors, also referred to as gene-based biosensors – or genosensors – are extremely complex devices comprising a unique type of sensing element. In a DNA-based biosensor, the receptor is composed of a fragmented DNA recognition layer which interfaces with target DNA by means of chemical interactions. Signals generated by this unique chemistry are converted into electrical values using sophisticated transducers and detectors, enabling accurate and ultra-fast detection of DNA.

This novel method of DNA detection is based on the binding of DNA strands via a range of complex mechanisms, including:

Adsorption
Crosslinking
Complexation
Covalent bonding

Innovations in nanoengineering have opened new avenues of exploiting these properties to immobilize DNA on interface/probe surfaces. This is the fundamental basis of DNA biosensors based on hybridization; the complementary pairing of DNA strands. Graphene has emerged as a suitable material for bioactive sensing applications, including serving as a substrate for immobilized nucleic acid in hybridization-type DNA biosensors. This holds high potential for the field of gene editing.

Using Graphene in DNA Biosensors

Self-assembled graphene nanolayers and functionalized carbon nanotubes (CNTs) are at the forefront of research and development into next-generation DNA biosensors. The unique molecular structure and bio-affinity of carbon-based mono- and few-layer materials makes them ideal substrates for DNA recognition layers.

With theoretically unmatched electrical conductivity, graphene may also serve the purposes of active sensing elements and field-effect transistors; moderating currents in real-time based on the unique in situ chemistry at the probe interface. The underlying mechanism of action is typically target amplification. This electrochemical method of DNA detection is already playing a critical role in clinical settings.

Want to learn more? Read our recent article on Single-Layer Graphene as a Sensor

Developers of new DNA sensors are increasingly utilizing graphene in unprecedented ways. One study has seen scientists combine functionalized substrates with clustered regularly interspaced short palindromic repeats (CRISPR) technology to design a biosensor with superior repeatability and precision, effectively eliminating the need for target amplification thus mitigating errors like amplification bias. DNA biosensing technology such as this could have dramatic implications for clinical, diagnostic, environmental, and forensic applications in years to come.

Graphene Materials for DNA Biosensors

Grolltex is one of the industry-leading developers of high-purity monolayer materials via chemical vapor deposition (CVD). Our self-assembled graphene materials are suitable for integration into various sensor types, including proof-of-concept DNA biosensors. If you would like more information about our graphene sensor capabilities, or wish to place an order, simply contact a member of the Grolltex team today.