Micropatterned reduced graphene oxide based field-effect transistor for real-time virus detection

Graphene, a new class of two-dimensional (2D) carbon crystal structure, holds a train of remarkable properties due to its fast electron transport, high chemical stability and strong mechanical strength. Herein, we report a real-time, rapid and sensitive biosensor for pathogenic rotavirus detection based on the micropatterned reduced graphene oxide field-effect transistor (MRGO-FET) which displays p-type behavior. Single layered and large sized GO sheets greater than 50 μm were prepared by a modified Hummers method, and through the photolithography and reduction process, an MRGO-FET was generated. After integration into a polydimethylsiloxane microfluidic channel, specific rotavirus antibodies have been covalently anchored to the graphene surface on which 1-pyrenebutyric acid N-hydroxysuccinimide ester was pre-adsorbed through π-π interaction. Injection of a rotavirus sample whose concentration ranged from 10 to 10⁵ pfu/mL led to a quick decrease in the source-drain current and then a gradual saturation. The lowest detection limit for rotavirus was determined as 10² pfu which is superior to the conventional ELISA method.