How Does Field Effect Biosensing Work?

FEB combines the capabilities of Graphene Field Effect Transistors (GFETs) and Biological Field Effect Transistors (BioFETs) into one.

Inherently digital, silicon transistors are the building blocks of modern electronics. They amplify electrical signals and enable switching between “on” and “off” states, for digital applications such as computing and transmitting cell phone signals.

GFET: Taking It to The Next Level

While transistors function well in electronics, silicon itself is unstable in air and water, causing transistors to perform poorly when placed in the conditions necessary to measure biology. GFETs eliminate this problem. A GFET has one simple design change from a typical transistor: Silicon is replaced with graphene, a nanomaterial that’s stable in air and water. This takes the capabilities of transistors to a new dimension, one where the transistor can be exposed to the natural environment around it.

Graphene transistor

BioFET: Making It Biological

But what good is exposure if the transistor can’t interpret and provide data about what’s happening? That’s where BioFETs come in. In a BioFET, the “on” or “off” state of the transistor is controlled by the binding interaction of biomolecules. When two biomolecules bind, the change in charge distribution on the transistor surface alters the current flow through the device, triggering it to be “on” or “off.” This means biology is decoded and delivered in instantaneous digital form!

BioFET with silicon surface

FEB: Bringing It All Together

While silicon BioFETs can interact with biology, they perform poorly in air and water. Cardea Insight biosensors combine the best of these two types of transistors, GFET and BioFET, into a proprietary digital technology called Field Effect Biosensing (FEB). With FEB, graphene biosensors are used to measure biomolecular interactions. Graphene is considered a “super material,” with high electrical conductivity and surface area that makes it extremely sensitive to even the smallest of electrical changes. Hence it has an exceptional application in detecting biomolecular interactions which currently depend on less sensitive, non-portable optical techniques such as Surface Plasmon Resonance (SPR), Bio-layer Interferometry (BLI) and Mesoscale Thermophoresis (MST).

BioFET with graphene surface

FEB in Action

Our Innovation Partners

Nanomedical uses Cardea’s proprietary FEB technology to power Agile R100, a personal assay system for characterizing small molecules and proteins for drug discovery in the biotech and pharmaceutical industries.

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Nanosens Innovations uses Cardea FEB technology to detect and measure interactions between CRISPR-Cas9 and its target (via the binding strength of gRNA), enabling the world’s first real-time quality assurance tool for CRISPR.

Agile R100

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