A cathodically polarized PANI-based lead ion-selective electrode: achieving high stability with antibiofouling...

Area of Science:

• Electrochemistry
• Environmental Science
• Materials Science

Background:

• Solid-state contact ion-selective electrodes (SC-ISEs) are vital for heavy metal monitoring.
• Electrode potential instability due to biofouling hinders SC-ISE development in real water samples.
• Addressing biofouling is critical for optimizing SC-ISE performance.

Purpose of the Study:

• To develop a highly stable and anti-biofouling SC-ISE for lead (Pb²⁺) detection.
• To investigate the role of polyaniline (PANI) in enhancing electrode stability and resistance to biofouling.
• To evaluate the performance of the PANI-based electrode under cathodic polarization for environmental monitoring.

Main Methods:

• Fabrication of a solid-state contact lead ion-selective electrode (SC-Pb²⁺-ISE) using polyaniline (PANI) in the ion-selective membrane (ISM).
• Application of cathodic polarization (-0.2 V) to the GC/PANI-Pb²⁺-ISM electrode.
• Evaluation of antibiofouling efficiency, standard potential stability, chrono-potentiometric stability, and Nernstian response slope.

Main Results:

• The GC/PANI-Pb²⁺-ISM electrode achieved a 98.2% antibiofouling efficiency under cathodic polarization.
• Excellent chrono-potentiometric stability (±0.5 mV standard potential deviation) and Nernstian response (30.7 ± 0.2 mV/decade) were observed.
• The electrode demonstrated superior stability and performance, suitable for practical environmental water monitoring.

Conclusions:

• Polyaniline (PANI) effectively acts as both an ion-to-electron transducer and an antifouling agent in SC-ISEs.
• Cathodic polarization is a viable strategy to enhance the stability and anti-biofouling properties of PANI-based SC-ISEs.
• The developed GC/PANI-Pb²⁺-ISM electrode shows significant promise for real-world heavy metal contamination monitoring.