Selective supramolecular interaction of ethylenediamine functionalized graphene quantum dots: Ultra-sensitive photoluminescence detection for nickel ion in vitro

Graphene quantum dots have attracted the researchers' attention due to its high stability, low cost and controllable photoluminescence performance. In this paper, we report the synthesis of ethylenediamine functionalized graphene quantum dots (E-GQDs). The E-GQDs is synthesized via hydrothermal treatment of the mixed solution of graphene quantum dots and ethylenediamine. The E-GQDs shows remarkable quantum yield (0.83). The quantum yield of E-GQDs is higher than quantum yields of most previously reported GQDs. Moreover, due to the coordination between Ni2+ and ethylenediamine, the PL of E-GQDs quenched via static quenching process. This makes the E-GQDs an alternative for ultra-sensitive PL probe of Ni2+ (detection limit: 3 x 10(-8) M) with high antijamming capability. We also demonstrated the good performance of E-GQDs in vitro detection of Ni2+.