“…20,21 Since the seminal report on use of graphene oxide (GO), a derivative of graphene, this compound has seen increasing application in biomedical areas, including cell proliferation and differentiation, drug delivery, immune response, and anticancer therapy. 15,18,20,[22][23][24] Significantly, GO has abundant oxygen functional groups, including hydroxyl, epoxy, carbonyl, and carboxyl groups. 25 The effect of GO can be modulated by modification of its oxygen moieties as well as altering chemical functionality on graphene layers.…”