▎ 摘　　要

The study of interaction between biomolecule and graphene is of great interest for future bioelectronic applications. Here, we report the adsorption properties of L-cysteine biomolecules on the surface of graphene sheet. Raman spectroscopy was used to characterize the intrinsic properties of graphene. We further performed the electrical transport measurement to investigate the effect of L-cysteine biomolecules on the graphene field effect transistors (FETs). We found that the charge neutrality point (CNP) is shifting towards negative gate voltage due to biochemical dopant which demonstrate n-type doping in the graphene film and the effect become prominent by increasing the chemical treatment time. The electron mobility of the graphene FET is drastically enhanced up to five times while the hole mobility is increased approximately twice as a function of treatment time. Therefore, the elevated values of mobility signifies the improvement in performance of the L-cysteine coated graphene based FETs. Thus, biomolecular treatment of graphene could be an effective approach to expedite for bioelectronic and biosensing devices. (C) 2017 Elsevier B.V. All rights reserved.