Binary RuO₂-CuO Electrodes Outperform RuO₂ Electrodes in Measuring the pH in Food Samples

Area of Science:

• Electrochemistry
• Materials Science
• Food Science

Background:

• Glass pH electrodes dominate the food industry but suffer from brittleness and high cost.
• Ruthenium(IV) oxide (RuO2) electrodes present a more robust and economical alternative.
• Further cost reduction and reduced toxicity are desirable for pH electrode materials.

Purpose of the Study:

• To evaluate the performance of Ruthenium(IV) oxide-cupric oxide (RuO2-CuO) composite electrodes for pH measurement in food samples.
• To compare the efficacy of RuO2-CuO electrodes against traditional RuO2 electrodes.
• To assess the impact of CuO incorporation on electrode durability, cost, and measurement accuracy in food matrices.

Main Methods:

• Fabrication of RuO2-CuO pH electrodes using screen printing technology.
• Application of a protective Nafion membrane coating on the electrodes.
• Experimental validation of electrode performance in various food sample types.
• Comparative analysis of measurement accuracy and response time against RuO2 electrodes.

Main Results:

• RuO2-CuO electrodes demonstrated a significantly higher rate of accurate pH measurements compared to RuO2 electrodes in food samples (nearly twofold).
• The incorporation of CuO did not compromise the response time of the pH electrodes.
• Accurate pH measurements were achieved across a wider range of food sample types using the RuO2-CuO electrodes.

Conclusions:

• RuO2-CuO composite electrodes are a viable and improved alternative to conventional glass and RuO2 electrodes for food pH monitoring.
• The use of CuO offers a pathway to lower-cost, less toxic, and highly accurate pH sensing in the food industry.
• These findings support the potential for widespread adoption of RuO2-CuO electrodes in food quality control and processing.