Photo-induced green synthesis of bimetallic Ag/Pd nanoparticles decorated reduced graphene oxide/nitrogen-doped graphene quantum dots nanocomposite as an amperometric sensor for nitrite detection.

The present study introduces a novel nanocomposite based on reduced graphene oxide, nitrogen-doped graphene quantum dots, and palladium and silver nanoparticles (rGO/NGQD/AgPd) as an electrocatalyst toward nitrite oxidation reaction. Metal nanoparticles were prepared via a green one-pot photochemical reduction procedure utilizing UV light and NGQD simultaneously as a reducing and directing agent. Formation of the nanocomposite was thoroughly demonstrated by the FT-IR, XRD, Raman, XPS, FE-SEM, and TEM characterization tests. Various electrochemical tests evaluated the efficiency of the prepared sensing platform on the surface of a gold working electrode. Sensitivity and limit of detection (LOD) were calculated to be 0.854 μA.μM-1.cm-2 and 0.052 μM, respectively, from the chronoamperometry data. Finally, the proposed sensor was successfully applied for the determination of nitrite ions in river and mineral water samples as natural water sources.