A novel strategy for the design of smart supramolecular gels: controlling stimuli-response properties through competitive coordination of two different metal ions

Abstract

By rationally introducing Ca²⁺ and Fe³⁺ into a supramolecular gel, a bimetal–gel CaFeG was prepared. CaFeG could reversibly “turn-on” its fluorescence upon sensing H₂PO₄⁻ with specific selectivity under gel–gel states through the competitive coordination of Ca²⁺ and Fe³⁺ with gelators and H₂PO₄⁻. Thus, CaFeG could act as a H₂PO₄⁻ test kit and could be utilised in rewritable security display materials.