Construction of a robust solid-contact carbonate-selective electrode based on the UV-curable membrane matrix with nanoporous gold substrate

The construction of the strong interfacial adhesions among the conductor substrate, solid-contact transducer and ion-selective membrane is required for developing the stable and robust solid-contact ion-selective electrodes (ISEs). Herein, a robust solid-contact CO 3 2− -ISE was constructed through the photocurable polyacrylate membrane attached on the mercapto polyethylene glycol acrylate (SH-PEG-Ac) modified nanoporous gold (n-PG)/gold electrode. The n-PG, acting as a solid contact, was fabricated by using the electrochemical alloying/dealloying method, and SH-PEG-Ac was covalently self-assembled on the n-PG film/gold electrode through the strong Au S bond and used as a reactive site for the covalent linkage to the polyacrylate-based ion-selective membrane through the UV photopolymerization method. The proposed solid-contact CO 3 2− -selective electrode displays a Nernstian potential response in the activity range of 5.2 × 10 −5 –5.1 × 10 −4  M CO 3 2− with the detection limit of 2.6 × 10 −5  M and the slope of 27.5 ± 0.6 mV/dec. The proposed electrode also exhibits satisfactory robustness, due to the anchored polyacrylate-based membrane in the nanoporous structure of the n-PG film. This work reports a favorable strategy to promote the interfacial adhesion among the electronic conductor, solid contact and ion-selective membrane, and is promising for developing other stable and robust solid-contact ISEs.