Electrical detection of biomolecular adsorption on sprayed graphene sheets

► We fabricated graphene field effect transistors with solution exfoliated graphene. ► The transistor enables us to characterize bio-molecular adsorption electrically. ► We studied solid-binding peptides as a molecular calibration tool. ► This sensor responded to the peptides comparably with conventional graphene sensors. ► The sensorgrams are verified by atomic force microscopy.