RuO₂ pH Sensor with Super-Glue-Inspired Reference Electrode

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Sensing

Background:

• Traditional pH sensors using ruthenium dioxide (RuO2) electrodes with cyanoacrylate coatings show limited pH sensitivity and poor performance in complex sample matrices.
• Existing differential pH sensors often struggle with reliability and accuracy when applied to diverse real-world samples.

Purpose of the Study:

• To develop a high-performance pH sensor as an alternative to conventional glass pH sensors and less effective RuO2-based designs.
• To create a robust, cost-effective, and simple sensor for reliable pH analysis across various sample types.

Main Methods:

• Fabrication of a novel pH sensor utilizing a RuO2 pH-sensitive working electrode.
• Integration of a SiO2-PVB junction-modified RuO2 reference electrode.
• Evaluation of sensor performance in common sample matrices, assessing sensitivity, hysteresis, and drift.

Main Results:

• The developed RuO2 sensor demonstrated excellent pH sensitivity of 55.7 mV/pH.
• Achieved low hysteresis (2.7 mV) and minimal drift (below 2.2 mV/h), indicating high stability.
• Performance comparable to commercial glass pH sensors in various sample matrices.

Conclusions:

• The novel sensor design overcomes the limitations of previous RuO2 electrodes in real-world applications.
• The developed sensor offers a promising solution for simple, cost-effective, and robust pH analysis.
• This advancement paves the way for improved pH sensing technologies in diverse environments.