A label-free immunosensor based on a graphene water-gated field-effect transistor

Electrolyte-gated graphene field-effect transistors are here proposed for biosensing applications. To this end, a label-free immunosensor based on this technology is employed for the sensitive and selective detection of IgG. Differently from the typical approach based on the bioreceptor immobilization onto a graphene layer, in this work sensitivity in the lower femtomolar range can be reached thanks to the formation of a closely packed layer of anti-IgG receptors anchored to the gold gate electrode.