Fig. 1From: Electrochemical and optical biosensors for early-stage cancer diagnosis by using graphene and graphene oxide(The copyright permission is obtained from Wei et al. (2015)) a The chemical process of graphene oxide and Graphene. b Schematic illustration where a low graphene oxide (GO) concentration exhibits a high adsorption of proteins in the left depiction. The right depiction illustrates a high GO concentration with low adsorption of proteinsBack to article page