Ion-selective electrodes based on l-tryptophan and l-tyrosine

Novel ion-selective electrodes (ISEs) based on amino acids have been developed. l-Tryptophan and l-tyrosine, which are amino acids, are employed as ionophores for solvent polymeric membrane electrodes. The proposed ISEs show rapid Nernstian responses for the Cu2+ ion over the concentration ranges of 3.0 × 10−4–1.0 × 10−1 M. These ISEs exhibit comparatively good selectivity with respect to alkaline, alkaline earth, and some transition and heavy metal ions and the ammonium ion. The ISE based on tryptophan also indicates the Nernstian response for the benzylammonium ion.

► This is the first report on characterization of polymeric membrane electrodes based on amino acids as ionophores.
► Novel polymeric membrane electrodes based on tryptophan and tyrosine exhibits the Cu2+ ion selectivity.
► The pH dependence of response of the polymeric membrane electrode based on tryptophan is examined.
► The polymeric membrane electrode based on tryptophan also shows a Nernstian response for the benzylammonium ion.