Stable Pb(II) ion-selective electrodes with a low detection limit using silver nanoparticles/polyaniline as the solid...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Solid contact-based ion-selective electrodes (SC-ISEs) are crucial for electrochemical sensing.
• Developing stable and sensitive solid contacts (SCs) is essential for improving SC-ISE performance.
• Silver nanoparticles/polyaniline (Ag@PANI) composites offer unique electronic and capacitive properties.

Purpose of the Study:

• To prepare and characterize SC-ISEs using Ag@PANI as the solid contact material.
• To evaluate the electrochemical performance of the developed SC-ISEs for lead ion (Pb²⁺) detection.
• To assess the stability, reproducibility, and real-world applicability of the Ag@PANI-based SC-ISEs.

Main Methods:

• Preparation of Ag@PANI composite material for the solid contact layer.
• Fabrication of a glassy carbon electrode modified with Ag@PANI (GC/Ag@PANI-II).
• Electrochemical characterization and performance evaluation of the GC/Ag@PANI-II/Pb²⁺-ISE for Pb²⁺ detection, including limit of detection, response slope, and stability tests.

Main Results:

• The Ag@PANI SC exhibited high capacitance and excellent electron transport.
• The fabricated GC/Ag@PANI-II/Pb²⁺-ISE demonstrated a low Pb²⁺ detection limit (6.31 × 10^-10 M) and a Nernstian slope (29.1 mV/dec).
• The electrode showed a fast response (< 5 s), good long-term stability over 3 weeks, and high reproducibility, with successful application in real sample analysis (97-109% recovery).

Conclusions:

• Ag@PANI composites serve as effective transducer materials for SC-ISEs.
• The synergetic effects of silver nanoparticles and polyaniline enhance the performance of SC-ISEs for trace ion detection.
• The developed SC-ISEs show significant potential for sensitive and reliable lead ion monitoring.