Graphite oxide multilayers for device fabrication: Enzyme-based electrical sensing of glucose

Abstract

In this paper, the use of graphite oxide multilayers as a transducer material for the fabrication of electronic devices is outlined. Graphite oxide flakes were produced in a solution-based exfoliation method optimized for large area thin layers with narrow size distribution. A dielectrophoretic technique was used for scalable trapping of the graphite oxide onto the microelectrode pairs patterned over glass chips. The graphite oxide trapped in between microelectrode gaps was subjected to a very rapid thermal annealing step in ambient in order to make good electrical contacts with source and drain electrodes. After this, the graphite oxide devices were characterized for their electrical transport using impedance spectroscopy and field-effect measurements in an electrochemical gate configuration. The conductivities of the graphite oxide devices were tested against the thermal treatment in air in order to determine a nominal burn-out as well as the optimal parameters for device characteristics. The devices were surface modified with glucose oxidase and deployed for sensor operation. This work suggests for the use of graphite oxide thin-layers as an easy and suitable alternative for the fabrication of electronic sensor platforms circumventing the dependence over tedious chemical and physical graphene oxide reduction methods. Schematic illustration of the graphite oxide (GrO) multilayer-based electronic chips fabricated over glass substrates. The chips were deployed as sensors for the electronic detection of glucose. Schematics not fit to scale.