A new fluorescent probe for distinguishing Zn2+ and Cd2+ with high sensitivity and selectivity

Abstract

A new fluorescence probe for distinguishing Zn²⁺ and Cd²⁺ is designed and synthesized. For the first time to our knowledge, this probe can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions, instead of by selective coordination alone, which may be interfered with and lose its selectivity easily in a complicated environment, providing a distinct recognition even by the naked eye for Zn²⁺ and Cd²⁺ with the sensitivity at the ppb level. This design strategy may initiate a straightforward approach for the selective detection of various metal ions with similar chemical properties in extensive applications such as environmental, industrial, and bio-science.