Xanthurenic acid: a natural ionophore with high selectivity and sensitivity for potassium ions in an aqueous solution. (4th January 2016) - Raju, M.
Abstract : Synopsis: A well-known tryptophan metabolite, xanthurenic acid, a natural non-fluorescent intermediate siderophore, showed a very selective turn-on response to K + over other competing metal ions and the detection limit of this natural ionophore was found to be 53 nM at physiological pH. Abstract : Xanthurenic acid (H3 L ), a simple natural molecule and a well known tryptophan metabolite involved in the biosynthesis of quinolobactin siderophore, was developed as an efficient "turn-on" fluorosensor for potassium ions in aqueous HEPES buffer solutions. The natural ionophore, H3 L, showed high selectivity for K + at physiological pH and in the context of interference from other competing metal ions, particularly Na +, the specific response ofH3 L towards K + did not change. The detection limit was found to be 53 nM. This study demonstrates the first example in which a non-cyclic system bearing monocarboxylate functionality was used as an efficient fluorosensor for the detection of K + in water.