A Flexible, Transparent Chemosensor Integrating an Inkjet-Printed Organic Field-Effect Transistor and a Non-Covalently Functionalized Graphene Electrode

This paper presents a novel chemical sensor that combines an organic, floating gate field-effect transistor and a functional graphene electrode, aimed at realizing the basic building block for novel biomedical sensor systems. A non-covalent functionalization of graphene with sensing peptides bearing a pyrene moiety is described as a way to provide graphene with chemical responsivity without affecting its electronic and optical features. Given the special properties of the materials and technologies used, and the intrinsic multi-modality of the active device, it is possible to develop a complete range of chemosensing devices by varying the chemical specificity of the immobilized receptor. The devices are fully flexible, highly transparent, and can be completely fabricated into large areas using cost-effective and industrially relevant techniques. A complete electrical characterization of the fabricated devices is reported, and their successful use as pH sensors is described as a representative example for demonstrating their sensing capability.