A simple approach for fabricating solid-contact ion-selective electrodes using nanomaterials as transducers

• A general method for fabricating nanomaterials based solid-contact ISEs is developed.
• The mixture of an ionic liquid and a nanomaterial is used as intermediate layer.
• The detection limits of the proposed sensors are in the nanomolar range.
• The developed electrodes exhibit a good response time and excellent stability.

A simple and robust approach for the development of solid-state ion-selective electrodes (ISEs) using nanomaterials as solid contacts is described. The electrodes are fabricated by using the mixture of an ionic liquid (IL) and a nanomaterial as intermediate layer, formed by melting the IL. Tetradodecylammonium tetrakis(4-chlorophenyl)borate (ETH 500) is chosen as an model of IL to provide strong adhesion between the inner glassy carbon electrode and the intermediate layer. Nanomaterials including single-walled carbon nanotubes (SWCNTs) and graphene were used as active ion-to-electron transducers between the glassy carbon electrode and the ionophore-doped ISE membrane. By using the proposed approach, the solid-contact Cu2+- and Pb2+-selective electrodes based on ETH 500/SWCNTs and ETH 500/graphene as transducers, respectively, have been fabricated. The proposed electrodes show detection limits in the nanomolar range and exhibit a good response time and excellent stability.

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