Figure 1.

Schematic illustration of synthesis of Gd-rGONSs; the procedure involves oxidation of graphite (G) (A) to graphene oxide (GO) and (B) via modified Hummers’ method. Graphene oxide (GO) (B) to reduced graphene oxide (r-GO) (C) (reduced and functionalized with amine functional groups). Dispersity of r-GO was enhanced by incorporating d-gluconic acid (GA) (D) and functionalized with pentetic acid (DTPA) (E). Gd³⁺ ions decorated over reduced graphene oxide nanosheets (Gd-rGONSs) (F) were obtained successfully as Gd³⁺ ions were chelated by DTPA.