Graphene quantum dots functionalized gold nanoparticles for sensitive electrochemical detection of heavy metal ions

Graphene quantum dots (GQDs) are emerging zero dimensional materials promising various novel applications due to their extraordinary physicochemical properties. In this work, novel conjugates of GQDs and gold nanoparticles (AuNPs) are synthesized and used for sensitive electrochemical detection of heavy metal ions (Hg2+ and Cu2+). Ultralow detection limit (0.02 nM with S/N = 6.25 for Hg2+ and 0.05 nM with S/N = 4.81 for Cu2+) and high sensitivity (2.47 μA/nM for Hg2+ and 3.69 μA/nM for Cu2+) have been achieved.