Conducting polymer ion sensor electrodes-III. Potentiometric sulfide ion selective electrode

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Science

Background:

• Sulfide detection is crucial in biological and environmental monitoring.
• Existing methods may lack selectivity or the ability to operate in diverse conditions.
• Conducting polymers offer potential for advanced sensor development.

Purpose of the Study:

• To introduce a new potentiometric sensor electrode for sulfide detection.
• To evaluate the electrode's performance, stability, and selectivity.
• To assess its suitability for microscale measurements in biological environments.

Main Methods:

• Electrochemical deposition of poly(3-methylthiophene) and poly(dibenzo-18-crown-6) films onto a low-melting-point alloy substrate.
• Fabrication of a microsize version of the electrode.
• Testing of electrode response stability, working temperature range, linear dynamic range, and pH tolerance.

Main Results:

• The developed electrode demonstrated stable response for up to 3 days.
• It operates effectively within a temperature range of 10-40°C.
• The sensor exhibits a linear dynamic range of 1.0x10⁻⁷–1.0x10⁻² M sulfide across a broad pH range (1-13) with high selectivity.

Conclusions:

• The new conducting polymer-based potentiometric sensor is effective for total sulfide measurement.
• Its microscale manufacturability and selectivity make it suitable for biological applications.
• The electrode shows significant promise for in-situ sulfide monitoring within biofilms.