Selective Fe²⁺Ion Recognition Using a Fluorescent Pyridinyl-benzoimidazole-derived Ionophore

Abstract

Fluorescent organic molecules that respond to changes in the <TEX>$Fe^{2+}$</TEX> concentration with selectivity to other abundant di-valent metal ions will offer the ability to understand the dynamic fluctuations of the <TEX>$Fe^{2+}$</TEX> ion in interesting media. The use of 6-Br-ppmbi, derived from 2-pyridin-2-yl-benzimidazole, for metal ion-selective fluorescence recognition was investigated. Screening of the main group and transition metal ions showed exclusive selectivity for <TEX>$Fe^{2+}$</TEX> ions even in the presence of competing metal ions. In addition, the requirement for low concentrations of probe molecules to detect certain amounts of <TEX>$Fe^{2+}$</TEX> ions make this sensor unique compared to previously reported <TEX>$Fe^{2+}$</TEX> ion sensors.