Researchers use graphene field-effect transistors to create a sensitive, noninvasive glucose-sensing platform
Researchers from Portugal’s International Iberian Nanotechnology Laboratory and Italy’s Istituto Italiano di Tecnologia have addressed the need for noninvasive, ultrasensitive alternatives to currently available glucose monitoring sensors used for continuous monitoring of diseases like Diabetes Mellitus and presented electrolyte-gated graphene field-effect transistors functionalized with glucose oxidase. The scientists developed an optimized fabrication process that integrates a 32-transistor matrix within a miniaturized 1000 μm2 footprint, ensuring high device uniformity while enabling detection in 40 μL analyte volume.
A comprehensive suite of techniques (including Raman spectroscopy, X-ray photoelectron spectroscopy, and water contact angle measurements) reveals the stepwise evolution of graphene chemistry and surface properties leading to the controlled immobilization of glucose oxidase. The team’s findings demonstrate p-type doping and tensile strain in the graphene channel across the nanomolar–millimolar glucose concentration range. The enzyme-catalyzed oxidation of glucose produces hydrogen peroxide in close proximity to the graphene channel, inducing a systematic shift in the Dirac point voltage toward more positive values. Under these conditions, the biosensor achieved an attomolar limit of detection and a sensitivity of 10.6 mV/decade, outperforming previously reported glucose sensors.
Source: https://www.graphene-info.com/researchers-use-graphene-field-effect-transistors-create-sensitive-noninvasive
