Rewritable security display material and Cl~- sensor: Based on a bimetal competitive coordination controlled supramolecular gel

摘要

By rationally introducing Mg~(2+) and Co~(2+) into a supramolecular gel, a bimetal-gel MgCoG was prepared. MgCoG could reversibly fluorescent "turn-on" sense Cl~- with specific selectivity under gel-gel states through competitive coordination of Mg~(2+) and Co~(2+) with gelators and Cl~-. The MgCoG could act as Cl~-test kit with high sensitivity and selectivity. The detection limit of the fluorescence spectra was 1.0×10~(-6)M (1 μM) for Cl~- anion. In addition, the MgCoG could act as rewritable security display material, when writing on the MgCoG film with a writing brush dipped in Cl~- water solution, a brilliant blue fluorescent writing image appeared. This fluorescent image could be erased by brushing Co~(2+) on the film again.