Sensing with liquid-gated graphene field-effect transistors

Liquid-gated graphene field-effect transistors (GFETs) with reliable performance are developed. It is revealed that ideal defect-free graphene should be inert to electrolyte composition changes in solution, whereas a defective one responses to electrolyte composition. This finding sheds light on the large variety of pH or ion-induced gate shifts that have been published for GFETs in the recent literature. As a next step to target graphene-based (bio-) chemical sensing platform, non-covalent functionalization of graphene has to be introduced.