Disposable Multi-Walled Carbon Nanotubes-Based Plasticizer-Free Solid-Contact Pb²⁺-Selective Electrodes with a...

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Science

Background:

• Lead(II) ions are significant environmental and health pollutants.
• Development of sensitive and selective lead sensors is crucial for monitoring.
• Plasticizer-free electrodes offer advantages in stability and reduced leaching.

Purpose of the Study:

• To develop novel potentiometric plasticizer-free solid-contact lead(II)-selective electrodes.
• To investigate the performance of electrodes incorporating multi-walled carbon nanotubes (MWCNTs) as an ion-to-electron transducer.
• To evaluate the detection limit, linearity, and interference of the developed electrodes.

Main Methods:

• Fabrication of disposable electrodes by drop-casting a methyl methacrylate-n-butyl acrylate (MMA-BA) copolymer membrane onto MWCNTs deposited on gold disk electrodes.
• Potentiometric measurements to determine electrode performance characteristics.
• Electrochemical impedance spectroscopy (EIS) for comparative analysis.

Main Results:

• The developed electrodes exhibited a sub-ppb detection limit of 10^-10 mol·L^-1.
• A Nernstian slope of 29.1 ± 0.5 mV/decade was observed in the linear range of 2.0 × 10^-10 to 1.5 × 10^-3 mol·L^-1.
• No interference was observed from gases (O₂, CO₂) or water films.

Conclusions:

• Plasticizer-free solid-contact electrodes incorporating MWCNTs offer a promising platform for sensitive and selective lead(II) detection.
• The developed electrodes demonstrate excellent performance characteristics suitable for environmental and clinical applications.
• The use of MWCNTs as an intermediate layer enhances the performance of lead-selective electrodes.