Graphene-quantum-dots-based ratiometric fluorescent probe for visual detection of copper ion

A novel dual-photoluminescence probe for Cu2+ has been developed, in which the graphene quantum dots with blue emission and CdTe QDs with yellow emission act as internal standard and probe, respectively. The photoluminescence probe exhibited selective sensing for Cu2+ with a limit of detection (3SD/k) of 5.3 x 10(-8) M and showed its potential application in visual imaging. The results indicated that the constructed probe can be employed for sensing Cu2+ by the naked eye, and also for monitoring intracellular Cu2+.