Ion-selective electrodes based on siderophores

Abstract

Siderophores are natural products used by plants and bacteria to transport iron across cell membranes. One class of these, the mycobactins, are hydrophobic and were judged to be suitable for inclusion in the organic membrane phase of a liquid ion-exchange electrode responsive to iron(III) ions. When tested, the electrodes had no response to iron, but did respond to salicylate with a sensitivity of ca.–29 mV per decade. The selectivity for salicylate over other anions was unusually large for a liquid membrane electrode and the effect of anion structure on the extent of interference was investigated, with implications for the mechanism of the electrode.