A new nano-composite potentiometric sensor containing an Hg2+-ion imprinted polymer for the trace determination of mercury ions in different matrices

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 x 10(-9) mol L-1 and a linear analytical range from 4.00 x 10(-9) to 130 x 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. (C) 2015 Elsevier B.V. All rights reserved.