A novel, simple and very sensitive carbon paste sensor composed of nanomaterials (graphene nanosheets and alumina nanoparticles), an Hg2 +-ion imprinted polymer, as a sensing modifier, and an ionic liquid, as the binder, was prepared and used for the potentiometric determination of Hg2 + ions in a wide variety of real samples. For the investigation of the ion-to-electron transducing ability of graphene nanosheets and ionic liquid on the electrode surface, the electrochemical impedance spectroscopy measurements were done. Under the optimized conditions, the suggested nano-composite sensor presented a detection limit of 1.95 × 10− 9 mol L− 1 and a linear analytical range from 4.00 × 10− 9 to 1.30 × 10− 3 mol L− 1 with an excellent Nernstian slope of 29.72 mV decade− 1. The suggested mercury sensor was successfully applied for the highly sensitive determination of trace amounts of Hg2 + in different real samples with satisfactory results.
