New Hg2+-Selective Chromo- and Fluoroionophore Based upon 8-Hydroxyquinoline

Abstract

A new 8-hydroxyquinoline derivative having an appended boron−dipyrromethene function has been prepared, and its metal ion sensing properties were investigated. The designed compound exhibited pronounced Hg²⁺-selective on−off-type fluoroionophoric properties among the representative transition- and heavy-metal ions in aqueous dioxane solution. The fluorescence was efficiently quenched more than 98% with 5 equiv of Hg²⁺ ions, and the detection limit was found to be 5 × 10^-6 M in a dioxane−water (1:3, v/v) solvent system. The ionophore also showed a selective chromogenic behavior toward Hg²⁺ ions by changing the color of the solution from light amber to red, which can be detected with the naked eye.