Design and construction of nickel hexacyanoferrate – Starburst PAMAM dendrimer modified gold electrodes for the potentiometric detection of potassium in aqueous media

Potentiometric sensors for potassium detection were prepared by chemical modification of polycrystalline gold electrodes with sub-monolayers of 3-mercaptopropionic acid or 2-aminoethanethiol (SC and SA, respectively) followed by the covalent attachment of PAMAM dendrimers (generation 4.0, DA, and 3.5, DC, respectively) in order to obtain films suitable for further electrostatic adsorption of nickel hexacyanoferrate (NiHCF) complexes. The characterization of the resulting electroactive layers by cyclic voltammetry (CV) experiments showed that the use of dendrimers in the synthesis of the films not only enhances the surface coverage of NiHCF when compared to thiol modified electrodes, but also the electroanalytic performance of the modified surfaces for the detection and quantification of potassium in aqueous medium under controlled ionic strength (I) conditions.