Wireless Graphene-Based Quantum Capacitance Sensors for Continuous Glucose Monitoring

E.J. Olson, D.A. Deen, M.A. Ebrish, A. Basu, Y.C. Kudva, P. Mukherjee, S.J. Koester
University of Minnesota, US

Keywords: graphene, glucose, sensor, wireless

Summary:

We describe a revolutionary concept for in vivo biosensing that utilizes the quantum capacitance effect in graphene to realize an ultra-small passive wireless sensor. The unique properties of graphene make it attractive for sensing applications. However, nearly all prior graphene sensors utilize “wired” configurations. Recently, we proposed using the quantum capacitance effect in graphene to realize variable capacitors (varactors) that can be used to create ultrasmall, passive, resonant sensors with wireless readout capability. Due to their potential for extreme miniaturization, graphene-based varactors are extremely promising to overcome limitations of current continuous glucose monitors, which have slow response time and require subcutaneous electrical contacts. The goal of this research is to demonstrate the viability of graphene quantum capacitance varactors for ultrasmall, wireless continuous glucose monitors. In this abstract, we demonstrate the surface functionalization of graphene using glucose oxidase (GOx), and observe the production of hydrogen peroxide from the GOX-functionalized graphene surface using chemiluminescence measurements. We have fabricated GOx-functionalized graphene varactors and show that the devices exhibit a strong response when exposed to varying concentrations of hydrogen peroxide. The results are an encouraging step toward the realization of a device for continuous passive monitoring of blood glucose.