Electrogenerated chemiluminescence of luminol at a gold nanoparticle-carbon nanotube-graphene composite modified glassy carbon electrode in neutral solution

In this paper, a graphene modified glassy carbon electrode (GR-GCE), a carbon nanotube modified glassy carbon electrode (CNT-GCE), a carbon nanotube-graphene modified glassy carbon electrode (CNT-GR-GCE), and a gold nanoparticle-carbon nanotube-graphene modified glassy carbon electrode (GNP-CNT-GR-GCE) were prepared and characterized by FT-IR, atomic force microscopy (AFM), and electrochemical methods respectively. Electrogenerated chemiluminescence (ECL) of luminol was comparatively studied at these modified electrodes in neutral solution. The results revealed that carbon nanotube could intercalate into the graphene film and improve the conductivity of the CNT-GR composite significantly. The CNT-GR composite is an ideal matrix for the deposition of gold nanoparticles. At the GNP-CNT-GR-GCE, the effect of GR on luminol ECL is more predominant than that of CNT while the electrocatalytic effect of GNP on luminol ECL is well preserved. These nanomaterials exhibit a good synergic effect towards luminol ECL, which is more efficient than that of the sole material. The volume ratio of GR and CNT, the amount of modified suspension, the presence of N-2 and O-2, and the supporting electrolytes could affect luminol ECL. Finally, the mechanisms of luminol ECL at the modified electrodes were proposed.