title: Ion-selective electrodes based on L-tryptophan and L-tyrosine.
abstract: 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 Cu(2+) 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.
authors.affiliation: Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1Omiya, Asahi, Osaka 535-8585, Japan. kawakami@chem.oit.ac.jp
authors.forename: Takayo
authors.initials: T
authors.lastname: Moriuchi-Kawakami
authors.forename: Yu
authors.initials: Y
authors.lastname: Tokunaga
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Shibutani
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002412:Cations; D017736:Ion-Selective Electrodes; D007476:Ionophores; D008567:Membranes, Artificial; D008670:Metals / Q000032:analysis*; D011199:Potentiometry; D000644:Quaternary Ammonium Compounds / Q000032:analysis*; D012680:Sensitivity and Specificity; D014364:Tryptophan / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D002412:Cations; D007476:Ionophores; D008567:Membranes, Artificial; D008670:Metals; D000644:Quaternary Ammonium Compounds; D014443:Tyrosine; D014364:Tryptophan