Schematic illustration of the GR-MIP sensor fabrication using an electrodeposition technique, which exhibited good recognition of l-dopa.

A novel dual-photoluminescence probe for Cu(2+) 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 Cu(2+) with a limit of detection (3SD/k) of 5.3 × 10(-8) M and showed its potential application in visual imaging. The results indicated that the constructed probe can be employed for sensing Cu(2+) by the naked eye, and also for monitoring intracellular Cu(2+).