The holy grail of pyrene-based surface ligands on the sensitivity of graphene-based field effect transistors

Abstract

Graphene has received intensive research interest due to its remarkable charge mobility, and the efforts in the use of graphene-based field effect transistors (GFETs) for the sensing of biological biomarkers is on the rise. Because of the high non-specific protein adsorption on graphene, well-defined surface modification strategies have to be implemented to benefit from the excellent electronic transfer characteristics of GFET devices for specific detection of biomarkers. Surprisingly, while pyrene-based ligands are the most widely used graphene surface anchors for sensing-related applications, no systematic investigation on the reaction conditions employed and the influence of pyrene functionalities has been reported so far. As this is one of the essential steps for efficient receptor integration and sensitive sensing, by using GFET-based analysis of cardiac troponin I (cTnI) as the model compound we will show that an optimized pyrene–maleimide ligand incubation time on graphene of 2 h gives the best sensing performance. This study not only will be a guideline for researchers interested in GFET biosensors but also will hopefully allow industrial GFET development in a faster path.