Performance comparison of solid lead ion electrodes with different carbon-based nanomaterials as electron-ion exchangers

Carbon-based nanomaterials with carboxylation or chemical modification are widely used as electron-ion exchangers of solid electrodes. For reducing the complexity and dangerousness of the intermediate layer preparation, different original carbon-based nanomaterials are dispersed in deionized water. They are applied in the fabrication of Pb²⁺-selective electrodes. Because the contact angle of graphene reached 132.5^◦, the Pb²⁺-selective electrode of graphene used as an electron-ion exchanger showed excellent performance with a low detection limit of 3.4 × 10⁻⁸ M and a fast average response time of 42.6 s. The Nernstian response slope could reach 26.8 mV/decade, and the lifetime lasted for a month. Therefore, graphene suspension without any treatment can be used as the intermediate layer of solid-state electrodes, providing a reference for the preparation of other ion-selective electrodes.