SALICYLATE SELECTIVE ELECTRODE BASED ON A BIOMIMETIC GUANIDINIUM IONOPHORE

A biomimetic strategy was employed in the development of oxoanion-sele ctive ionophores containing the guanidinium functional group. These io nophores mimic the selective interaction observed between arginine res idues of proteins and oxoanions. In previous work, it was demonstrated that a structurally rigid guanidinium ionophore exhibited excellent h ydrogen sulfite selectivity (Anal, Chem. 1994, 66, 3188-3192). Herein, we describe guanidinium-containing ionophores that are selective for the oxoanion salicylate. The ability to rationally design anion-select ive electrodes through this biomimetic strategy, and to both alter sel ectivity and improve response characteristics through structural chang es to the ionophore, has been demonstrated. H-1-NMR complexation and m odeling studies were used to examine and correlate the selectivity obs erved with the structure of the guanidinium compounds.