Remarkable potassium selectivity of ion sensors based on supramolecular gel membranes made from low-molecular-weight gelators without any ionophore.

Supramolecular gels formed by low-molecular-weight gelators bearing diamide groups were used as ion-sensing membranes for the first time. Even though no special ionophore was added to the membranes, excellent ion selectivities for K(+) over alkali metal ions were realized with the sensor systems.