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Developing the First Graphene Biosensors

By July 27, 2017September 5th, 2021Blog
Nanomedical Diagnostics Case Study

In the fiercely competitive world of drug discovery, researchers who can quickly bring new drugs to clinical trial at reduced cost are ahead of the game. In order to evaluate new drugs, researchers typically test candidate compounds using large and complex optical systems that can require days of training to use and hundreds of thousands of dollars to purchase.

Graphene-based systems have the potential to offer an alternative method of testing with none of these drawbacks, but up until recently, graphene has proven difficult to harness. While graphene offers excellent electrical conductivity, high surface area, and unique biocompatibility, integrating it into standard high-volume production processes has been impossible. Until now.

Not Garden-variety Graphene

Partnering with Nanomedical Diagnostics, we have broken through to solve the long-standing puzzle of how to integrate graphene into traditional MEMS processing, enabling us to manufacture this novel sensor.

Everyday graphene can’t be used for biosensors if highly sensitive results are the goal. Only defect-free graphene will work. Given that graphene is a relatively new material, the reality of depositing other materials on top of it was uncharted territory for our company. Rising to the challenge, we worked closely with Nanomedical Diagnostics to develop processes that, when complete, produce several hundred chips from each finished wafer, and the first commercially available biosensor.

graphene biosensors rogue valley microdevices memsDeveloping a Label-Free Kinetic Binding Assay

Nanomedical Diagnostics had stringent requirements and a unique design in mind when creating its Agile R100, its label-free kinetic binding assay. For example, exposure to standard lithography chemistries was out. A high sensitivity to solvent residue required the application of novel capping and passivation techniques. Nanomedical Diagnostics also required a process that would enable graphene growth to make large-scale manufacturing possible.

An important consideration is that the Agile R100, like the human body, uses an all-electrical technique to transmit data. As such, it measures conductance rather than changes in mass, enabling detection in complex samples and of small molecules with no lower size limit.

Agile R100 checks all the boxes. It’s small enough for a benchtop. It’s affordable and does not require special training for use. It also uses small sample sizes, giving small-molecule therapeutics researchers more control over the characterization of their molecules to make more informed and earlier decisions in the drug discovery process.

Although there was very little useful information on incorporating graphene into MEMS device fabrication when we first began working with Nanomedical Diagnostics, we embraced our voyage into the unknown because we were excited about working with a talented team on such a worthy project. We look forward to future journeys with new partners.

Read the case study here.