Screen-printed ruthenium dioxide electrodes for pH measurements

Plastic, fully screen-printed, disposable pH sensors based on ruthenium dioxide are described. Application of thick-film technology results in highly reproducible fabrication of the sensors. The electrodes enable fast measurements, with good sensitivity (51 mV/pH), in acidic and neutral solutions (linear range of response up to pH = 8). No interferences from alkaline cations, commonly accompanying anions and complexing ligands were observed. The pH measurements were strongly affected by reducing substances. Some potential analytical applications of the sensors are pointed.