Critical assessment of graphene as ion-to-electron transducer for all-solid-state potentiometric sensors

Carboxy-functionalized graphene was used as a solid contact for potassium ion-selective electrodes with poly( vinyl chloride) based membrane. Transducer layers were obtained simply by application of a dispersion of graphene derivative in water. Analytical performance of thus obtained sensors was compared with that of all-solid-state sensors with typical transducer materials: poly(octylthiophene) applied as chloroform solution, conducting polymers available as aqueous dispersions of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) ions or polyaniline. It was found that all sensors tested were characterized with similar analytical parameters. Carboxy-functionalized graphene contact layer was in some respect similar to polyaniline one, what most probably results from the presence of pH sensitive groups in both materials. (C) 2012 Elsevier B.V. All rights reserved.