▎ 摘　　要

Graphene quantum dots (GQDs) have been prepared from graphene oxide (GO) and characterized by standard analytical techniques. The size of the prepared GQDs ranges from 2-10nm. Aqueous dispersion of GQDs exhibited excitation-dependent emission behavior. Emission intensity of the aqueous dispersion found stable for the examined duration of about four months. GQDs exhibited selective recognition of Fe3+ and Cr3+ out of various common ions such as alkali, alkaline-earth and transition metal ions in aqueous medium through fluorescence quenching. The lower limit of detection of Fe3+ is 1 mu M and that of Cr3+ is 4 mu M. [GRAPHICS]