Nafion as a protective membrane for screen-printed pH-sensitive ruthenium oxide electrodes

Solid-state electrodes have gained attention in past decades for application in pH sensing as a miniature and mechanically stable alternative to conventional fragile glass electrodes. As a material for solid-state electrodes ruthenium oxide has shown the best characteristics. In this study we investigated the sensitivity and stability of RuO2 screen printed electrodes, produced from the commercially available conductive paste. To enhance the performance, electrodes were coated with Nafion protective layer. Influence of the concentration of Nafion coating solution, drop-casted on the sensitive area of the electrode, was investigated. RuO
₂
pH electrodes covered with Nafion layer have shown super- Nernstian response and longer response time, which come into agreement with the result published by other authors previously.