Ion-Selective Electrodes with Three-Dimensionally Ordered Macroporous Carbon as the Solid Contact

Electrodes with three-dimensionally ordered macroporous (3DOM) carbon as the intermediate layer between an ionophore-doped solvent polymeric membrane and a metal contact are presented as a novel approach to solid-contact ion-selective electrodes (SC-ISEs). Due to the well-interconnected pore and wall structure of 3DOM carbon, filling of the 3DOM pores with an electrolyte solution results in a nanostructured material that exhibits high ionic and electric conductivity. The long-term drift of freshly prepared SC-ISEs with 3DOM carbon contacts is only 11.7 microV/h, and does not increase when in contact with solution for 1 month, making this the most stable SC-ISE reported so far. The electrodes show good resistance to the interference from oxygen. Moreover, in contrast to previously reported SC-ISEs with conducting polymers as the intermediate layer, 3DOM carbon is an electron conductor rather than a semiconductor, eliminating any light interference.